well, I'd say the Amigas themselves will be worth very little, since there are an awful lot of them around. The most you'd expect for the A500 is about 20 UKP, more for the A2000.
The VXL-30, I'd say 30 - 50 UKP (but this is just a guess)
Same goes for the A1200 accelerator, possibly a bit more...
GVP G-Force 040 I reckon you could get a good price for, 50 UKP ++
The other bits...I don't really know
These are guestimates, perhaps someone else can chip in - Amigamad watches stuff, perhaps he can help out :-)