Whats the $'s i would need to drop on a half decent usb microscope?
Depends what you mean by a usb microscope. Most of the little hardwired ones are toys. There is some interesting information here
http://micro.magnet.fsu.edu/optics/intelplay/index.html about the QX3 which was subsequently replaced with the QX5 which I believe is phased out. A similar toy with similar alterations may be intersting and useful.
There are all sorts of things one can do once they grasp the basic concepts of microscopy.
I bought an old Leitz with 2 garbage objectives and 2 good ones and no power source and no light tube to convey the light to the prism but it had a valuable phase contrast condenser worth upwards of a $1000. I paid $168.
I pulled the socket which the light bulb seated in and found that there was a regular house current bulb which would fit. I wired the socket to a household dimmer switch, put in a 50 watt bulb (original was 15 watts). I used a piece of stainless steel drain pipe for the light tube. I then only needed a cheap portable diffusion filter between the prism (where the light comes through) and the condenser.
I used some other objectives from my collection and volla had a $4000 microscope which many have drooled over.
$168 + $10.00 (dimmer switch) + $3.00 (bulb) + $10.00 (drain pipe)
+ $1.00 (diffusion filter) + $250.00 (used objectives) = $442.00