I've ran across a couple, but would like to ask people here if you have any recommendations for good websites that host/sell files for full commercial use?
You might have better luck just hiring someone to create files for you rather than 'cold calling' designers. Not sure if anything like you're looking for exists as it would seem odd to have a marketplace of designs for sale as any company buying them would probably want exclusive rights to sell the product.
Learn CAD my guy! No asking for permission if you made the design!
I make between $500 and $1k a month in profit selling my original designs. 3D Printing is so much more rewarding when you can turn ideas into products instead of finding files people made
I mean, it's not really generic. Have you bought commercial prints and had a good experience with a site/seller? That's the info I am looking for. I can search all day but I'd love to hear what other people have experienced so I'm not just throwing my money at a site that won't deliver quality files.