Those prices look pretty good, not sure how they perform though.
I had to get new fronts a few weeks ago after a track day. I really wanted to stick with the excellent Michelin Pilots - but no where had them in stock and they were VERY expensive even if they managed to get some in. I ended up with Pirelli P Zero Rossa's (£160 each) which I am reserving judgment on until I get a few more miles on them, but they seem pretty good so far. I am going to need rears soon (just turned 10,000 miles) so will probably match them up with more P Zero's. I have found Conti sports to be very good 'budget' choice so may consider going for four of them and keeping the Zero's for the track. The problem with tyre choice (unless replacing like for like) is you pretty well have to take a chance and hope you get on with them, otherwise you're stuck with them for some time.

Simon.