Do you know of any obscure useful websites?

For all my fellow mechanical engineers out there, Custom Parts is an incredible tool for estimating tooling and production costs for injection molding, die casting, stamping, you name it. For runs all the way from 50 parts to 2 million I've found the estimates there to be consistently within 10% of the quotes we've gotten from suppliers

Edit: Corrected link, that's what I get for going off memory lol