A Harbor Freight 1x30 isn't really a bad investment for a beginner, especially a young kid with a limited budget. I got one for sharpening but have been using it for making handles and I'm just starting to use it for grinding bevels. It's probably about the most barely adaquate grinder you can use for grinding bevels but it's by far the cheapest. Make sure you get a 20-25% coupon online or from the paper, to save more money.
Check all the bolts and set screws right out of the box, most of mine were loose and I didn't realize until the drive wheel nearly fell off.
Cheap 1x30 belts are available on Amazon and other online supplies.
The little dinky platen that comes on it may have to be modified, I had to grind one side of mine down.
I also cut off the back side of the work platform so I could tilt it up towards the belt. If you clamp your knife tang to a piece of angle iron you can use the platform as a guide to keep yourself steady.
If you like grinding and upgrade to a 2x42 or 2x72 later, the little 1x30 can still be useful for working on handles, sharpening, or other small grinding needs.