3200's are very easy to sell when they are good ones, I have people fighting over them. Thing is, there are very few good ones around, simply not possible to find many good ones in my experience. I've sold 6 or 7 3200's in the last year or so as that's all I've been able to find. There are lots of 3200's which remain unsold usually as they're not great examples.
4200's sell very well if they're facelift or at least 'MSP' 2003 onwards cars, there's a few 2002 cars unsold that have been for sale a while. If they're cambiocorsa, good colour combo, good history and condition, they sell well.
Sorry, I'm rambling, answer to your question Andy, no, 3200's sell better if you have a good one. Never ceases to amaze me.