Chipmunk!!! What else?
Much though I love DH's classic, for 30K there's no contest - Yak 52.
The Chippy isn't half as much of an aeroplane as the '52, and costs far more in maintenance.
The Yak costs in fuel - but as a sole owner, that would be still a lot cheaper per hour than the Chippy.
Bangs per buck - nothing comes close to a Yak!
SSD