what sort of valuation are you looking for here?
Do you want individual prices on all those figures? do you one one price for the whole lot?
either way, the £2-5 ballpark quote per figure is pretty much correct, with any ORIGINAL weapons being worth ~£5-10 alone.
i'd suggest look at ebay loose sales, or just save time and price every loose figure up at say £4 (excluding anything last 17 or obviously more valuable) then reduce anything that doesn't sell thereafter. If you just want it all sold quickly as one lot, you'll be looking at a dealer giving you around 50% or market value at best (i.e. <£2 per figure). your best bet is individual small sales, but this obviously means a few trips to the post box et al