It's probably worth considering rolling resistance. There's varying claims out there, up to 0.5 mpg. I don't believe that, but let's say you could improve from 6.2mpg to 6.4mpg. if that is possible with tires and you calculate 120,000 miles per year and $4/gallon fuel that equals $2419.35 in fuel savings per year. Even if you could just improve by 0.1mpg with tires that would save $1200/yr in fuel.
Look up OOIDA 1800-444-5791 their membership is $45/year and you can get national account price's with them as a member
Anyone ever see the damage does to all the fairings on a tractor, when a recap blows out? Oh yeah, you saved a little on each tire, then did a thousand dollars worth of damage later on to the tractor. I would never put recaps on my tractor. Maybe the trailer, since there is less to damage with a blow-out. I don't care what Bandag tells you, recaps are not worth the hassles.
Love's has a pretty good price on tires right now. I don't recall if they sell recaps or not. If you can't afford to buy 8 new tires at one time, then buy 1 or 2 until you can replace all of them. If money is tight and you cannot afford new or caps, you may check around to see if you can find used tires at a decent price. I would check with tire dealers where someone such as Fed Ex or others have traded in tires. You can sometimes find tires with a fair amount of tread at a decent price. Don't buy at a truck stop unless absolutely necessary. Find a dealer that is away from the interstate. Wingfoot has shops around the country. Prices at their shops are less when you get away from the truckstops.
Yes, you can see a .3-.4 improvement with virgins over recaps. I just put on a set of 4 used virgins (Bridgestone M710's with 10/32) to replace a blown recap and very badly worn caps. I had all Michelin cases, XZA, XDN and XDA. It happened on the road during a trip and a set of 4 were twice what they wanted for a "get home tire" I went from 6.2-6.3 to 6.6-6.7 mpg. And that's running gross weights between 75 and 80K. I am sold enough on it, my next set of tires will be a set of virgin M710's. They will pay for themselves.
So you ###-uming everyone hauls cheap?? If you never been on a tough financial spot in your life you never lived.