I've recently started to collect the 1/18 UT Mclarens. What i can say for sure is that overall, the mint, boxed LMs appear to command the highest prices.
I recently picked my one up on eBay for EU81,00, (£GBP55.00/$US93.00) , including insured shipping. It's a Series 1, i.e. twin blade rear aerofoil, and centrally mounted roof ariel, mint undisplayed condition, in the original box with the door strapping still in place.
No disrespect, but if you can afford it, go for the UTs over Maisto or Guiloy; it's worth it, (yes, i've seen/owned the others).
For a complete listing of the 1/18 UT Mclarens go to...
http://www.scale18.com/cgi-bin/searc...t8=-1&sort9=-1
UT 530-133180 ut133180b appears to be the rarest, if the 1/200 figure relates to the amount made and issued; less than a real one!
Still waiting for a reasonably priced 1/12 to come up, but they're all going for over £GBP250 on eBay etc.