It is not the voting, it is the counting
I have had to do some work around vote counting in the 1990es in a couple of European countries, so let me provide a bit of perspective.
The usual approach used to be not to buy anything. At all. The procedure in the 1990-es was:
1. Grab 20 desktops from a school computer class, library or a suitable company on a one week lease.
2. Boot them off external media, enter the votes as they are counted and dump the vote counts onto remove-able media producing a print receipt including checksums for all data.
3. Collate the votes at CO using a similar setup.
We investigated using networks, etc and discarded it as too complex to set-up for a 3 days election event and disband after that.
The whole thing worked a treat in the DOS days as you could boot your election counting software off a 3 inch floopy together with the OS.
Windows threw a massive spanner into these works by severely limiting what you can do here. You cannot just show up, boot a windows live CD, run the vote counting process and leave. That is a violation of the Microsoft license agreement. Do not even get me started on windows update, connect to the mothership and license enforcement either.
The right way would have been to show MSFT a HUGE three finger salute and switch to something that works fine off live media. I am not mentioning the L word as it is not the only option. Unfortunately, for a huge list of reasons (including vicious lobbying by local MSFT account teams up to government level) this has not happened(*).
Well, now 15 years later (that is when the lobbying efforts, etc started) we reap what we sow. We do not have a non-Windows alternative (or a special license exemption allowance to use Windows for this app and boot any number of copies anywhere for 3 days). So we have to go back to PRE-1990es tech (thank you Billy Boy and Ballmer) to run elections.