There is a local dealer in my town that has a couple very clean Z's with low miles. May be too far from you but you can check them out online at www.paulscarcare.com
. View by make and see for yourself.
2001-Black-Z3 3.0 w/ only 12,000miles for $25K
2000-Red-M Roadster w/ 56,000miles for $22K
The owner is a friend of the family so I can negotiate pricing for you if need be. I have bought my last 2 Bimmers from him.