Per-user backup pricing over 5 years, calculated
Most Microsoft 365 backup vendors don't publish an exact price, so instead of guessing at numbers to attribute to a named competitor, this page does the arithmetic on the one vendor that does publish an exact, official rate (Microsoft itself) and adds one clearly labelled illustrative scenario for the common per-seat model, against Osiris's actual one-time price.
The one sourced number: Microsoft 365 Backup, $0.15/GB/month
Microsoft's own pricing page states $0.15 per GB per month of protected content for Microsoft 365 Backup, its native offering (full sourced comparison). That's $1.80 per GB per year. Computed at three realistic, steady volumes of protected content:
| Protected content (steady) | Per year | Over 5 years |
|---|---|---|
| 200 GB | $360 | $1,800 |
| 1 TB (1,000 GB) | $1,800 | $9,000 |
| 5 TB (5,000 GB) | $9,000 | $45,000 |
This assumes flat, unchanging data volume for 5 years, which is the conservative assumption: mailboxes and OneDrives almost always grow, so a real 5-year bill under a per-GB meter typically comes in higher than this table, not lower.
An illustrative per-seat scenario (not any named vendor's price)
"Per-user backup pricing" is usually discussed per seat, not per GB. No vendor compared on this site publishes an exact per-seat figure, so the table below uses $4/user/month purely as an illustrative, round, commonly-cited market figure, explicitly not attributed to Veeam, MailStore, Acronis, Keepit, AvePoint, Datto or NinjaOne/Dropsuite, none of whom publish one:
| Mailboxes | Per year at $4/user/mo (illustrative) | Over 5 years |
|---|---|---|
| 50 | $2,400 | $12,000 |
| 150 | $7,200 | $36,000 |
| 500 | $24,000 | $120,000 |
Against Osiris's actual price
Osiris Business is €250 once, with all updates included for as long as Osiris is actively developed, no renewal fee at all: €250 total across 5 years, and it does not change with mailbox count or protected GB (see full pricing). That's the entire point of a flat, one-time edition price against either kind of per-unit meter above: the gap between the two models widens as the organization grows, not narrows.
Frequently asked
How much does per-user backup pricing cost over 5 years?
It depends entirely on the rate, but any recurring per-unit meter multiplies by both time and growth: Microsoft's own published $0.15/GB/month for Microsoft 365 Backup comes to $9,000 over 5 years for a steady 1 TB of protected content, before accounting for data growth, which almost always pushes the real figure higher. A one-time licence like Osiris's does not have that second axis at all.
Why not list exact 5-year costs for Veeam, MailStore or the others?
Because none of them publish an exact public per-seat price. See each vendor's own comparison page for what is and isn't documented. This page computes real numbers only from Microsoft's own published $0.15/GB/month rate, the one exact price available, plus one clearly-labelled illustrative (not vendor-specific) scenario, rather than presenting a guess as if it were sourced.
Microsoft 365 Backup pricing: learn.microsoft.com, "Pricing model for Microsoft 365 Backup", accessed 2026-09-24. The $4/user/month figure is explicitly illustrative, not sourced to any vendor, and currency and unit basis (per-GB vs. per-seat) are not directly comparable: both tables are presented to show how a recurring per-unit meter compounds over time, not as a currency-matched claim.