At the big box stores absolutely they have it worked in to the prices. I have no idea if the local mom and pop shops are working that 2-4% into their prices or not.
Especially service companies. They tend to quote out "cash" (aka check/bank transfer) price and then add another 5% or so if you want to pay via card. There of course is very often an even cheaper "actual cash" price too you need to ask for if you are so inclined.