Michelle/Kimberly, I was looking at the economics for Park-N-Rides (on the TW Mainline Leg) thought you might be interested in this: According to Gary Choquette, it costs us in fuel 1420 Mscf/d for storage of 42,502 Mscf of gas.
Assuming a BTU factor of 1.00 and at a gas cost of $3.00 per MMBTU--fuel costs amount to $4260/day.
Adding O&M to this (assuming 1/3 fuel cost), the total cost of this storage to us is ~13 cents.

Park-N-Ride Economics