Using @anon45965781's example of 40 users, and just using the online store... you have too decide what's most important to you. Lifetime licensing costs, if you used FileMaker for 15 years, is still lower using the annual volume license ( which is essentially 1/3 the cost of a full perpetual license ).
If you want your annualized cost to be lower, buying the maintenance every year after buying the perpetual license is your best move with FileMaker. Maintenance is 1/5 the cost of a full license. So if your client updates more than once every 6 years, it's cheaper (annually) to just pay for the maintenance. Annualized cost after the initial purchase would be ~$4k/year for 40 users. The other benefit to this approach, is that if you stop paying, there is no requirement to uninstall FileMaker.
Now none of this includes a Site License, if the company only has 40 employees. The costs are typically even cheaper. For example, our current cost is significantly less than $5/month/user.
Quick comparison ( does not include multi-year purchases which include additional discounts ):
AVL ( Annual Volume License, non-site license ) @ 40 users.
Annual cost: $5,760
Lifetime cost over 15 years: $86,400
Monthly cost per user: $12
Note: Always update to date version ( important when OS versions are no longer available to install )
Perpetual License ( with Maintenance, non-site license ) @ 40 users
Initial cost ( year 1 ): $17,280
Annual Maintenance cost ( other years ): $3,456
Lifetime cost over 15 years: $65,664
Monthly cost per user: $36 ( year 1 ), $7.20 ( maintenance years )
Note: Always update to date version ( important when OS versions are no longer available to install )
Perpetual License ( no Maintenance, non-site license, upgrade every 4 years ) @ 40 users
Initial cost ( year 1, 4, 8, 12, 16-likely paid near end of year 15 ): $17,280
Lifetime cost over 15 years: $86,400
Monthly cost per user: $36 ( year 1, 4, 8, 12, 16 ). $0 ( year 2, 3, 5, 6, 7, 9, 10, 11, 13, 14, 15 )
Note: Only able to update every 2-4 versions, and are out of support for ~half the time ( important when OS versions are no longer available to install )
Site License discounts are also typically higher, so the numbers would be lower than all of the examples above. Also, contacting sales can often lead to at least some discount to get you in the door. There is also the option of getting your licenses through an FBA Partner. Again, none of that pricing is reflected on the online store.
This also doesn't account for the discount from reduced developer hours billed. That number can be pretty significant over the course of 15 years. All of it depends on our assessment, and the business owner's assessment of what's most valuable to them. For example, if you estimate that dev time is about 50% longer outside of FileMaker ( using a low number here for argument sake, because I know it's often longer ), a 60 hour project in FileMaker would take about 90 hours in . At a rate of $150/hour, it's going to cost an additional $4,500 in dev billable hours. This is a relatively small project. Now consider a larger project, 800 hours. The additional dev cost is now closer to $60,000 for that one project. What a business owner decides, is fine, but that all has to be part of the calculation. If you do additional projects in the future, there is additional savings. If it's ongoing development, the cost savings can be astronomical for the company and still providing you significant revenue.
Edit: One additional note that someone pointed out in a recent discussion elsewhere:
Claris does have a way to switch from annual to perpetual so in theory you just pay the difference then you remain on that version.
Edit 2: Fixed the license cost for the perpetual with maintenance 15 year cost that was a typo before.