you could also try something like this to get your 4 segments and maybe have a couple of hours in the warm sunshine:
PHL-STL-TPA-ORD-PHL same day (for example: Sat. 14 Dec works)
Flight: AA3033
Depart: (PHL)- Sat, Dec 14 6:35am
Arrive: (STL) - Sat, Dec 14 8:12am
Flight: AA 2944
Depart: (STL)- Sat, Dec 14 10:36am
Arrive: (TPA) - Sat, Dec 14 1:58pm
Flight: AA 1004
Depart: (TPA)- Sat, Dec 14 3:58pm
Arrive: (ORD) - Sat, Dec 14 5:44pm
Flight: AA 1344 on a Boeing 737-800 Jet
Depart: (ORD)- Sat, Dec 14 7:18pm
Arrive: (PHL) - Sat, Dec 14 10:08pm
prices out at $187.50 total on
www.travelocity.com - probably the same or less on aa.com and there you get the on-line booking bonus miles.
if you have not used it yet, the travelocity "dream map" is a pretty good tool to identify potential low cost "runs".
good luck....