I don't roll search so a handheld loupe serves me for that kind of looking. Thinking about it, I'd probably do something like a 10x stand magnifier for about $50, maybe with a handheld 5x for momentary additional magnification. Anything of interest goes into the "shoot me" pile. I'd want a field of view large enough to fit more than one coin at a time.
What you may not yet realize is that the pro-level images you see Ray, myself, the Captain, brg and the rest post, using the bellows/duplicating lens setup we recommend, are reduced to about 25% size to post here. The full-face images are more than large enough to do detail searching from, much less magnified detail shots. I have a 27", 2560x1440 monitor and can only fit half a coin shot on the screen at once.
Megapixels are excellent magnification.

So acquire an inexpensive manual setup for your initial searching. Search a batch, segregate and fullface image all the interesting ones, and then pack the coins away and examine the images at your leisure.