A couple of years ago there were some really cheap winter segment runs involving LBB/ACT/TYR/GRK and similar, connecting in DFW of course. It was in the vicinity of $30/segment, and you could fit 2 round trips in each day (long, painful days in ATRs...). They could also be nested inside AUS/SAT-DFW-X same-day turns. I'd expect something similar (though not that cheap) this year...

There are also some domestic routes from AUS or SAT that allow double connections. Many west-coast routes allow AUS-DFW-LAX-Y and many midwest routes allow AUS-DFW-ORD-Y. Catch a fare sale in the low 200s and you can get under $40/segment.