I purchased the "Carson MicroBrite Plus 60x-120x Power LED Lighted Pocket Microscope"[1] for $15 on Amazon.

I love it for its portability and durability-- I can pop it in my pocket or backpack and check out stuff on nature trails.

...Checking out its amazon page I also see this related, more powerful product for $20: "Carson MicroFlip 100x-250x LED and UV Lighted Pocket Microscope with Flip Down Slide Base and Smartphone Digiscoping Clip" [2]

And a search for 1000x microscope yields this $60 one "LCD Digital Microscope,4.3 Inch 1080P 10 Megapixels,1-1000X Magnification Zoom Wireless USB Stereo Microscope Camera,10MP Camera Video Recorder with HD Screen" [3]

[1] https://www.amazon.com/gp/product/B00LAX52IQ?psc=1

[2] https://www.amazon.com/dp/B015MS8O48

[3] https://www.amazon.com/PalliPartners-Microscope-Magnificatio...