I ordered a front and rear set of Heavy Duty Blisten's over the internet a few weeks ago. I purchased them for my F150. I paid about $60 each for them delivered. Ordering them over the internet saved me about $60.00 from paying retail prices, but I was not very happy with the vendor that I ordered them from.
I had never installed shocks before, but I did it all myself yesterday. It took me about 4 hours total. The fronts went pretty quickly, but the backs were an absolute *****.
One thing that I really disliked about the Blistens was their solution to keep the shaft from spinning while you tighten down the top nut. Most of the other shocks have a nut attached to the shock shaft to grip while you are tightening. This allows you to use a torque wrench with a socket. For the Blistens, you have to use an allen wrench at the top of the shaft to hold it in place while you use a offset ratchet wrench to tighten down the top nut. That design does not allow you to use the torque wrench. Stupid. Combine that dumb design with the fact that Ford left about 3" of space to work with in the rear, and the frustration factor set in pretty early.
Oh well, The truck rides much better now. I was at 130,000 miles on the original 9 year old shocks.
Ordering online will save you money.