Here is my opinion on how many:
If you have a couple you play with, fine. If you have some you use and have one of each boxed for collection purposes fine. Someone is hoarding who has has "stacks" of them, especially stacks of them in original boxes. How many you actually gonna use ?
I not trying to dampen the Christmas spirit, but, you seem to write a lot of posts villainizing and labeling folks who have more Amigas than you do. How many Amigas makes an Amigan evil?
Most of the Amigas in my possession were rescued from certain oblivion over the last 25 years. I'm not sorry for it. I intend to preserve them deep into the future.
On a positive note, I value your expertize that you have shared generously with me and other Amiga users. You seem like a well rounded and balanced person otherwise. 
Sour grapes don't become you.