I am stuck behind the company firewall and can't currently view some of the sites I will mention, so I will have to update this answer this evening. I post now, because I won't be home from the office for 14 hours or more, so you might have found it before then, from what I am about to say. If so, please post here.
Much as I like Lazarus, you best bet (probably your only bet, if you use 3rd party VCL) is Delphi itself.
1) Long ago, Borland gave away Delphi for free, both on the web and on magazine covers (they also gave away for free Kylix, which was cross platform Delphi, which supported both Windows and Linux - long since abandoned, but possibly of interest, although Lazarus is almost certainly superior).
So, Goggling for something like
Delphi 7 giveaway free download should do the trick/. I will race you to see who finds it first ;-)
This appears to be a video telling you “How to get delphi 7, completely free“ Please note that , being in the office, I have not viewed this video.
I can’t check if this one is legal
You get the idea, just keep goggling.
2) Failing that, try eBay.
3) Or, if you only need to recompile once, rather than have an on-going solution, you might try a trial version of the current Delphi & import your projects (although something that old might not be supported).
4) Failing all of that, you could buy the Starter Edition (see this page for comparisons), which is still far too expensive, imo. https://www.embarcadero.com/app-development-tools-store/delphi
I will update this evening, when I can Google without the firewall