I've mentioned this gun to my local gun dealer. He says he's sold them in the past but had no comment on how good/bad they were. Seems he said he sold them in the low $400s, which means they can be found in the $375ish range.
As the owner of a S&W AR-22 & a GSG-5L Carbine (MP5 lookalike in .22), the little Puma really appeals to me.
I think you numbers are a little off for current guns.
Straight dealer on the one shown is $479 from Jerry's Sport Center.
I wouln't mind trying one, wish they were $100 less.....but that really goes for everything...haha.
Jerry's can be a little high, but even so...AIM's $519 seems like a very fair price.