That's possible, although i've never seen fake wallet.dat sold at such low price on both this forum and various website from search engine.

That's one reason why there should be.

And personally i'd say near $0 since they need to fill it with fake data either manually or using script.

What's the cost of feeding files with fake, arbitrary data?

How about altering Ian Coleman's code?
He could insert the seeds from an Excel file

Ian Coleman could be altered to return wallets given a seed.csv, but it doesn't return balances, and I don't know if OP wants that.