check this one out i bought one and it is really handy.it does 100x and very light one.under $7 should be the best deal
Cambridge Educational Academic Microscope - eBay (item 120379750308 end time Feb-23-09 17:20:25 PST)

Cambridge Educational Academic Microscope - eBay (item 120379750308 end time Feb-23-09 17:20:25 PST)