found this $241 for 5284m actual & 5740 m (with 500 min) which is 4.2 cpm - you would arrive at 9:43 am on 3/6 though:

Boston (BOS) to San Diego (SAN) - Mon, Mar 5

US Airways Boston (BOS) to Philadelphia (PHL) - Mon, Mar 5
US Airways 1605 Dep: 1:30PM Arr: 3:15PM 1h 45m Embraer RJ-190 Economy (R)
Layover in PHL 2h 40m

US Airways Philadelphia (PHL) to San Diego (SAN) - Mon, Mar 5
US Airways 155 Dep: 5:55PM Arr: 8:57PM 6h 2m Airbus A321 Economy (R)

San Diego (SAN) to Boston (BOS) - Mon, Mar 5

US Airways San Diego (SAN) to Philadelphia (PHL) - Mon, Mar 5
US Airways 154 Dep: 10:15PM Arr: 6:07AM 4h 52m Airbus A321 Economy (R)

Layover in PHL Tue, Mar 6 2h 8m

US Airways Philadelphia (PHL) to Boston (BOS) - Tue, Mar 6
US Airways 1112 Dep: 8:15AM Arr: 9:43AM 1h 28m Embraer RJ-190 Economy (R)

Cost per passenger (including taxes & fees) $241.20
Total cost for 1 passenger $241.20