Currently running Yokohama AD08 Advan Neova's on my sprint Clio (due to tyre regulations) and they are surprisingly good road/track tyres. Not tried them in streaming wet conditions yet but they seem fine and grippy on the road in the recent random snow flurries etc, whilst being far superior on track to the Toyo Proxies I was running on my previous golf sprint car. Bearing in mind I cant go for 888's or RSR's due to regulations, I dont think I am missing out on a massive amount of outright grip and they certainly fit into your budget.
FWIW I actually got them cheaper, fitted, from the National tyres website. All of the usual suspects for buying tyres (Camskill etc) may look cheaper, but once you factor in fitting they all looked more expensive.