I like the Ideal strippers, but often for the Teflon wire we use some cheapo "plier" style ones I bought a pile of years ago, when we gave an amp building class. Look like these:
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.harborfreight.com%2Fmedia%2Fcatalog%2Fproduct%2Fcache%2F1%2Fimage%2F9df78eab33525d08d6e5fb8d27136e95%2Fi%2Fm%2Fimage_17561.jpg&hash=b287b540582cebc4616d22ffc269f7f2841a32d3)
Main thing is to get something that is sized so it will cut the Teflon but won't nick the wire right where the insulation gets cut. The cheapos are adjustable so you can get them set just right.
As for cost, here's a thread I found on stripper prices -
http://forums.anandtech.com/showthread.php?t=1639812