Thanks for the great diagrams @LotusGaurdian , it becomes much more clear now. Thanks to your post, I looked up image regression and learned a new concept!
Also, it’ beyond my current capabilities to suggest concrete fast.ai snippets etc 
, but just as a general direction, would it make sense to turn this into a multi-class prediction and each prediction represents a price range? So, instead of ‘goldfish’ we take ‘goldfish’ to mean “$120-130” ? To make it finer grained, make the number of categories larger and that’d squeeze the range accordingly?
There was an answer to a similar question previously, not sure if it fits your scenario exactly, but might help in moving things forward a bit?