Performance cars in general...

[french]

seem to be on the up lately, even the seemingly unloved C32 Amg is shuffling up in price. I think most AMG's are especially the SL's also 996TT are going mad over the past year, along with the 'M' car's ... was it the low oil price ?

 

[AMGeed]

I think you could be right. There was a trend of rising fuel prices that, until the oil price drop, looked like making fuel extremely expensive. Had the price kept rising, I think we could well be seeing £1 60+ per litre by now.
Big V8's and exotic cars were only being bought by those with a descent disposable income due to running costs. The cars were cheaper as they were hard to sell.

I have noticed the price of E55's have risen since I bought mine two years ago. Wouldn't surprise me to find I could get more for it now than I paid back in 2013 should I wish to sell.