Wow! That's a great deal. Thank you, stockmanjr.

Here is some additional information from Expedia:

- Fare is valid for travel between PHX and LGA or JFK
- Fare basis code is TE14SNX
- Fare is $146.98+11.02(US)+11.50(XT)= $169.50 based on a four-segment routing
- ROUTING 6 FROM PHX-CO-DEN-CO- VIA DTT/HOU/MSP-CO- OR VIA HOU-CO-ATL/BNA/CHI/CMH/DFW/IND/MKC/MSY/SDF/STL/FLL/MEM/ORL/RIC/TPA/DAY-CO- TO -DTT-CO-NYC*
OR TO CLE-CO-NYC*
- Travel between 8/1 and 11/15
- 14 day advance purchase
- Saturday night stay required, 30 day max stay
- No day, time, season, or blackout restrictions

I booked:

Thursday
CO 1808 PHX 0530a IAH 1006a
CO 1969 IAH 1059a LGA 0329p

Sunday
CO 1973 LGA 0430p IAH 0731p
CO 1493 IAH 0826p PHX 0904p

on eService online for $169.50. The telephone agent quoted me $574.00 for the same itinerary! I should have booked it on biztravel.com, as the ontime guarantee would be nice to have transiting LGA.