My opinion is that the price of amiga hardware will continue steadily drop from now on and never recover. Why? A number of reasons.
Because WinUAE is now so compatible and easy to use on modern cheap PC's it makes the original hardware a bit pointless, except for us nerdy types.
Floppy Disk Drives are dying at an alarming rate and disk boxes full of pirated disks on crappy media are rotting to pieces. ADF's are easy to find on the internet and now more people than ever are connected. So using real hardware is getting harder while emulation is getting better and easier.
And increasingly people can plug their PC into the VGA port of the living room telly (LCD flat panel) for big screen amiga fun.
The only saving grace for real hardware is CompactFlash as hard drives. This makes an A600 or A1200 slightly attractive to the casual retro nostalgia seeker, but not that attractive IMO.
I'm thinking of selling up my A1200 rig myself - would never have dreamed of doing that 5 years ago! Only thing stopping me is that it wouldn't fetch enough to bother.