Is there really a reason to commercialize / have ads running on this site?
I had to research the market when I was buying a server for myself a couple months back, so here is my analysis:
The hosting itself could be done on a server costing not more than $40/m at the extreme end assuming DPR like levels of activity. An annual crowdfunder could cover that.
As for image storage, Hetzner's storage boxes are a great value, starting at $3.50/m for 1 TB to $20/month for 10TB of storage.
At 10MB per image, that works to 100,000-1,000,000 total stored images.
I'm available to help setup the server. I think it's important to pick a reliable, cost affordable option from the outset so the community doesn't needlessly have to maintain larger expenses.