Well, thanks. Microscopes open up a whole new side of your reefkeeping. You may think you don't have many animals in your tank, but there are probably millions.
Better microscopes make the experience much better. You might try a used equipment auction at a nearby university or something. They often upgrade their equipment, but there's nothing wrong with 20-30 year old microscopes so long as the optics are good. I got an old Bausch & Lomb compound stereo for a really decent deal at an auction. The one I'm using at the moment is surprisingly good for a mid-price scope. It's a Celestron with the LCD screen instead of eyepieces. It has a built-in camera and the photo and video is really easy, which is why all this is on the cheap scope and not the B&L.
Good luck and let me know if you have any questions.
Oh, one other thing. I you do decide to get a scope, Ron Shimek sells an article on microscope keeping for a few dollars that's fantastic.