I can see where you are coming from with the whole price thing.
Personally, I think the demand is higher for R32's these days. It's obviously not because of the price difference, because if you wanted something newer (ie. 33) you can quite easily afford the money.
I could never buy a 33 GTS-T. Never have and never will be a fan of them. The only thing I would most likely prefer is an RB25. I probaby could of been close to buying a R33 GTS-T with the money I paid for mine. I could of bought one as I had plenty more money from the sale of my old car.
I would rather a R32 anyday over a 33 even though, yes, the potential of an RB25 may be greater for dollar to dollar it still doesn't out weight the fact that I dont like the general look of a 33.
I have found that most people that dont like Skylines tend to prefer either 32's or a 34 GTR's. Within the last few years 33's have become affordable and everyone has them. I think maybe people are asking more as they feel their "clean example" might be worth a good dollar as its becoming a rarity to find a mint example. I know of plenty of average GTS-T's that have gone for under 10k, manual & turbo... but most needed touching up etc etc..
For someone to find a good combination of nice paint, tasteful mods and a tidy interior, the value may be increased. Problem is I would say, all the shit heap owners think they can get the same dollar..