I went out in an '11 plate M-Sport Highline demonstrator the other day and was quite impressed actually. Although granted that's a bit more than his budget allows.
One of my friends had a Z4M Roadster for a while and he loved it, went from a fairly serious Subaru and didn't regret it in the slightest. Said that the price of dealer servicing was a little bit of a shock to the system though after self-servicing/specialist servicing costs on the Subaru.
Edit, just noticed the budget.
I'm not 100% what's available for his budget but I'd be looking at the biggest bang for buck and try to get one with the 3.0 engine with some desireable options fitted.
Cheers,
Grant