Stop lying, I'll give you a little hint that you are lying, The smallest size of wallet.dat file is about 90 KB, so how can you create wallets with sizes less than that? You are viewing .dat files, not compressed files?
Source of info
Lets see:
| | | ~size | | | #TX |
fresh | | | 96KB | | | 0 |
regular | | | 2MB | | | ~300 |
spam[1] | | | 421MB | | | 195508 |
So, about half of the data you sell is not for wallet.dat files.
Going back to the rest of the files, it is impossible to brute force password if it is not easy (numbers and some words) and you know a part of it, otherwise you waste the hardware resources. Can you open those files and view the amount of money with them?
Finally, even if it is of economic benefit, you can achieve more profits by using some walletrecovery services.