As a recent buyer of the A2A Spitfire and Warhawk, I can confirm that they are extremely fun and interesting to fly - and I mean that with all sincerity. If you have any interest in these warbirds, (im guessing we all do here) you have to give them a go.
That said, it's quite a lot of money to outlay. But if you already have FSX, just buy the a2a/accusim product you want, install the freeware airports that most interest you, and you're good to go.
p.s. anybody know why i keep setting my P-40 engine on fire?