Indeed it's true that Coleman fuel (white gas) costs substantially more than unleaded fuel. That's due in part to the more limited market for the stuff, but also to its higher degree of refinement. For the price of a new stove that would take unleaded fuel, you could run white gas through your older Peak 1 for a very long time and still come out ahead. Your break-even point probably is on the order of ten gallons of fuel or more.
Or, you could get a Coleman Feather 442 Dual Fuel stove. It's a nice little single-burner stove with that tank-below-burner design that some campers like. Coleman is closing them out for $40a good price (www.coleman.com). So you could save dough on the stove, then let your inner cheapskate run wild with unleaded gasoline.