Jenny's right, price less tax is true cost to compare state to state (avg price less tax by state go here;
TruckMiles.com - Daily Fuel Prices by ProMiles ). TA's have the best discounts using Comdata negotiated by Panther. I'll run to near empty in our st trk to get the best price. Ran to Miami the other day, fueled at the Marianna FL TA coming in, got a load out picking up in Tampa going to Cali, waited to fuel up in Marianna again since the Tampa TA was .14/gal higher, about 1154 mi.s. We've never had a problem with the idea of picking up junk in the bottom of the tank.
I understand seeming to be hit harder out of wallet quartely, but IFTA, your gonna pay at the pump (except OR and IN, remember there advertised prices are less some taxes, fuel surchges) or pay quartely, either way, it's the same total in the end based on mi.s per state, so I don't fuel based on what I'll owe at end of quarter but rather based on who is cheapest base cost after tax and discounts. In depth explanation here if care to read;
LESS ifta trying to understanding - IFTA - Fuel Tax - Let's Truck
I like TA's showers better then others, which I know isn't saying much, so I used to fuel whenever I could squeeze 50 gallons in. This year it occurred to me I could SQUEAK a little more when I walk if I fuel less often (provided I have accumulated enough shower credits to get by) because Comdata charges a $1.50 fee every time it is used so I can by a $4.00 meal at the STeak and Shake each month woohoo!