Hurm, I'm not sure about this. Its more on the fact that gameshops would have these to repair Wiis that are proving to have lens problems.

Unless you're using an original Wii, not modified, i would say that you can try asking gameshops if they can change the lens for you. If its a modified wii, pretty sure its the crap disc quality.

I think there's more luck to be had online. Gameshops most likely won't sell away their spare parts. Huhu.