I agree but i have always wonder why M11A1 lose so much value. there are variations in quality between the ASG/KWA/KSC but the cheapest i have seen and ASG in stock is £135, a KSC is about £180 and the mags start at £40 (not in UK more like £50.00) hell the proper silencers are £40ish if you can find one. You are right they aren't massively skirmishable which means a second hand one should be relatively unused but yet to sell they have to be dirt cheap.I picked one up with 3 mags, the right suppressor, & a matching shoulder holster for £75, yep it was a monster bargain, but I quickly sold it on, tbh they're not that skirmishable, silly rate of fire means you need a ton of mags.
For £200 I'd be expecting about 6 mags to make it worthwhile.