[QUOTE=FastJake;13506715 Any decent LBS should have axles with cones and locknuts as a complete set for under $10. Then of course the QR skewer. [/QUOTE]
I doubt it's going to be that easy.
The trick is to find the right axle. Most solid axles have a different thread pitch than most hollow axles. You'll definitely want to keep the same cones and locknuts because finding replacement cones to fit your solid axle hub's dust cover is an exercise in frustration. Hollow axles with the right thread pitch to fit your cones are available, but you might have to look for them.
The next issue is axle length. It has to be long enough to nest in your bike frame's dropouts but short enough to not extend beyond your dropouts AT ALL. Some lower end bikes have pretty skinny dropouts so you'll probably have to trim your new axle to get the perfect fit that's required.
Assuming you have horizontal dropouts, I strongly strongly recommend holding out for a genuine Shimano (or Campy) quick release skewer. They're not that much more expensive or hard to find and they really do clamp a lot more tightly.
If you're planning to QR the front wheel too, take a close look at the axle first. Some nutted front hubs use a smaller diameter axle which makes conversion to QR a lot more complicated.
Last edited by Retro Grouch; 11-18-11 at 08:02 AM.