Well, for the US market (may be different in the UK), personally I'd sell it in two or maybe three lots.
The only thing I might split by itself would be the accelerator, along with any specific RAM you might have for it.
I'd put the trapdoor FPU/RAM card back in the A1200 (I'm assuming it's not being used right now, as you state there is an accelerator currently in the machine) and sell it together with the odds and ends of software, as a good retro starter system.
Also throw in the SCSI CD ROM, SYQUEST and the rest into the A1200 system lot, if the A1200 still has SCSI after removing the accelerator. If not, throw those into a 3rd lot, but I wouldn't expect to get much (if anything) for those under any conditions. They are way to easy to scavenge for free out of systems people are throwing out every day.
Once again, though, that's a US view. Things are of different scarcity overseas.
