Re: Good thing for Linux
The cost of _finding_ a skilled reverse-engineering developer who is willing to undertake the work on contract is a challenge for a small business owner, let alone budgeting for the legitimate costs that the developer will incur while doing the work.
In addition, even if the base formats were to be reverse-engineered, if the original developer decided (for understandable IP protection reasons) to put in any amount of encryption (or even some well-placed obfuscation of critical code, parameters, or key data structures), then the reverse engineer would be faced with yet another set of hurdles, and the costs would go through the roof.
I could easily see such an effort, undertaken by a single developer, to run to $10k or $15k, or perhaps even $25k or more.
In my judgment, the best thing to do is to find some expert systems software assistance (which, while costly, will be far less so than an entire reverse development effort), and virtualize that Windows 98 machine so that it can easily, safely, and forever be run on a modern hypervisor.
Alternatively, hire a cheap offshore data entry team (or put it up for Amazon's Mechanical Turk) to rekey all the data into a modern application.