MSRP was starting at 50K new. Might as well add 4-6K and get a 2001 911 cabriolet. There’s one on eBay right now with 42k miles and buyout price $26,991.
I wouldn’t get an early Boxster. They are quite underpowered. If you can drive stick, for the price of a 2001 Boxster you can get a 2005 (maybe 06) S2000, which is equally fun and worlds apart in terms of reliability and maintenance costs.
How about BMW M3 E46? They really took a dive b/c of the spike in gas prices and the competition from new 335i. 2003 M3 could be found for high teens.