What a rent-versus-own calculator must show you before its answer means anything
Four things a software cost calculator has to show -- the seat count, the source and its date, which figure it picked, and the cost of the owned side -- worked through on our own, including the exclusion that makes it under-represent the expensive end of the market.
Anyone typing a rent-versus-buy question into a search box wants one thing: a number that tells them whether to keep paying monthly or pay once and be done. Every calculator that turns up is built by somebody who sells one side of that answer, and ours is no exception -- we sell the owned side. That does not make the arithmetic wrong, but it means the honest way to judge any calculator, including ours, is not by what it concludes. It is by what it shows you before it concludes anything. A calculator that will not show its working is not a calculator; it is an advert with a plus sign in it.
The four things a calculator has to show
| What it must show | What happens when it is hidden |
|---|---|
| The seat count behind a per-seat price | A per-user figure with no user count is not a price, it is a fragment |
| Where the figure came from and when | You cannot tell a current quote from a stale one, or a real page from a guess |
| Which vendor's figure was picked | A cherry-picked cheap tier flatters whichever side picked it |
| The cost of the side being sold as free after purchase | A one-time price with no upkeep line looks cheaper than it is |
The seat count
Thirteen of the 44 rows on our own calculator are per-seat vendors, and each is shown at a stated seat count. The page says so plainly: "per-seat tools are shown at the stated seat count -- your seat count may differ." That sentence matters more than any single price on the page. A per-seat monthly figure with no seat count attached is not a price at all -- it is a fragment of one, and multiplying it by the wrong number of people is how a buyer talks themselves into either tool for the wrong reason.
Where the figure came from and when
On our calculator, every row's fetch date and the verbatim quote it was taken from live on the product's own page, not on the calculator itself. That split is deliberate: the calculator is for comparing, the product page is for checking. If a calculator will not tell you when a competitor's price was read, or will not let you find the sentence it was read from, there is no way to know whether you are looking at this month's number or last year's.
Which vendor's figure was picked
Ours states its method in one line: monthly figures are "each product's highest cited competitor price." Say plainly what that does to the result -- it is a choice that favours us. Picking the highest cited price for each row, rather than the cheapest tier a shopper could actually land on, makes the subscription side look as expensive as it can honestly be shown to be, which makes the one-time licence look better, sooner, than a cheapest-tier comparison would. That is not a hidden thumb on the scale; naming it here is the point of this section. A calculator that will not tell you which figure it picked, and why, is hiding exactly this kind of choice.
The cost of the owned side
The one honesty note that costs us the most to print is this one: "Owning adds self-hosting duties (backups, updates, a server)." A calculator that shows the licence price as the whole cost of owning the software is lying by omission, even when every number on the page is accurate. The server, the backups and the update discipline are real costs. They are usually smaller than a subscription's ongoing fee, but usually smaller is not the same as zero, and a page that implies zero is not being honest with you even if it never states it outright.
The exclusion that matters most
Our calculator leaves rows out on purpose: "Quote-gated vendors with no public price are excluded entirely rather than guessed." A vendor that will not publish a price and only quotes one after a sales call cannot be put on a chart honestly. Guessing at that figure -- taking a rumoured number, an old review, or a plausible middle estimate -- would corrupt not just that row but the credibility of every row next to it, because a reader who catches one guessed number stops trusting the rest of the page.
The honest consequence of that exclusion is worth stating rather than leaving implied: a calculator built this way under-represents the most expensive end of the market. The vendors most likely to be quote-gated are often the enterprise tier, priced highest of all, and they are the ones missing from the chart. That is not a flaw we can fix by guessing; it is the price of not guessing.
The numbers, labelled as arithmetic
On 27 of the 44 rows on our calculator, one month of the competitor's subscription costs the same as, or more than, the entire one-time licence sitting beside it. That is a straightforward comparison of two published figures, not a projection of what either side will cost over a year -- it says nothing about month two.
Every figure in this section was read from the calculator on 2026-09-07, and each row's own fetch date and verbatim quote sit on that product's page rather than here, for the reason given above. The widest gap on the page is Specta at $99.00 once against Jasper PIM at $999.00 a month. The narrowest is the one worth just as much space, because it is the honest case rather than the flattering one: Leavora at $99.00 once against Factorial at $8.00 a month for one seat. At that gap, owning takes over a year to pay back in pure subscription-avoided terms, and for a single person using the tool lightly, it might never be worth the trouble of running a server for it. A calculator that only ever shows you rows like the Specta one and quietly drops rows like the Leavora one is not showing you a market, it is showing you a highlight reel.
Try the Specta demo ↗Live, on sample data, no sign-up.
When a calculator should not decide it for you
A break-even month, on its own, is not a reason to buy anything. Three situations where the arithmetic above should lose to a plainer judgement:
- A low per-seat tool at one seat. The Leavora-versus-Factorial row above is the pattern: at a single seat, a cheap per-seat subscription may simply be cheaper for as long as you use it, full stop.
- A business with no server and no wish for one. Self-hosting is a real duty, not a formality, and a business that has nobody to own backups, updates and a server should weigh that against the licence price honestly rather than assume it nets to zero.
- A tool you expect to stop using within six months. A one-time licence is a bet that you will still want the software later. If you already doubt that, a month-to-month subscription you can cancel is the lower-risk choice regardless of what the break-even row says.
None of that is a reason to distrust arithmetic in general. It is a reason to treat a break-even month as one input next to the ones a calculator cannot measure: whether you want to run a server, and whether you will still be using the tool by the time it pays for itself.
The calculator itself is open to walk through with your own seat counts and your own list of rows ticked. It does not collect anything by default; it will email you the rows you ticked only if you ask it to.