I just bought a 60x-100x with adjustable focus off ebay for about $8.00 with shipping. Has a LED. Works good, just hard to hold steady and focus unless you're on a flat surface.
I think you want at least a 30x one.
Heres a link to one im thinking about getting from one of RIU seed banks. 60x-100x for only $20, AND it has a LED!
http://www.speedyseedz.com/index.php/miscellaneous/420-science/420-scope/420-scope.html
anyone have one of these ^^?
if it's like $25-$30 i'm gonna be pissed lol.