I have to fly SAT-MCI or STL, leaving 8 Nov, have to return 12 Nov as late as possible (can overnight somewhere else, but have to initally leave on the 12th).

I've found some decent fares, in the ballpark of $200 all in (NW is a little lower, DL is a little higher). Since I am getting a refund on this trip of $200, I figure why not toss in a few extra segments and get some more miles while I'm at it. I'll gladly pay the difference if it's not too much over $200.

Messing around with ITA, I can't seem to add any additional segments without the price increasing an extra $200. Since I don't have KVS, or can't seem to find any routing rules, is there someone who may be able to help me out, or at least point me to where I can find the routing rules? I'm sure the fare buckets are sold out when adding the segments, but I still can't seem to come up with anything worthwhile.

Anyone have time to help me find a good way to stretch this trip out?