I have 17 pairs of Z-Coil's, the shoe with the spring heel. If you've seen me at a show, you see me flying around like an Energizer bunny constantly. I can do miles on concrete and never think about it. I have been in Z-Coils for about 10 yrs now. Open heel, enclosed heels, tennis shoes, sandals, clogs, mary janes, hiking boots, work boots, dress shoes- about 4 styles, and now the cowboy boot. If you peak in Hunter, I wear my black tennis shoes. Even Mary and Bob Sansevere saw me in them and went and got some, they'll never go back. yes, if you go to a store and buy them they are VERY expensive. But go anyway, get fitted to the correct size, find out the way your heel needs to be placed. Then when you're done, shop on *Bay and Craig*list, they are all over the place, the 300-400 shoes are around 200 or way under. I have bought most of mine under $75.