+1 to eBay.
It's been a few years since I needed one, but I received a complete unit with frame and fan in good condition for $150 shipped. Used from a high-rated major seller should be affordable and good.
Here's one from a seller I've been happy with. The one in photo looks a bit dirty, but the complete unit like that is probably the best bet if you don't want to do $$$ for new.
https://www.ebay.com/itm/162645132902?
I don't know this seller, but looks good:
https://www.ebay.com/itm/166189637043?
A couple other sellers that I highly recommend:
https://www.ebay.com/str/qualityporscheparts
https://www.ebay.com/str/specializedgermanrecycling