Fred,
There might be something to be said for an old school microscope. You would have a stage to hold the blade, usually multiple magnifications and possibly interchangeable objective lenses. More important you have a mechanism to focus that is reasonably precise. The problem is that, even used, a decent microscope will cost a bunch more than $50. I was looking at some that had not been made for 15 years that were selling for between $350 and $500 depending on the lenses you get.

Be aware that all of the solutions that I sent link to will be a bit fiddly and require you to get used to them. I like the 60 to 100 unit (simlar to what CBWX posted), but the depth of field is very shallow. It can be hard to get the entier bevel in focus (width) at one time. Lighting is very important. Changing the way the LEDs shine on the edge will completly change what scratch pattern you can see. Not only that but everything is upside down and backwards. I sometimes has a hard time finding and following the bevel along the length of the blade (I don't use it enough and my hand are not as steady as they once were)

The VEHO clone has similar issues. Lots of folks have spent far more on a stand for it than they did buying the camera. Again, focus and lighting are critical.If you look, you can see some of the photos that Clay took with his Dino-Lite. He shows that just adjusting the lighting can reveal a whole different perspective. You can use it pretty well by hand and just throw the image up on a monitor and do OK with it. It certainly give the most magnification bang for the buck. If you tame the thing, it also allows you to document your edges with photographs.

Just be aware, you will have to get used to and figure out the best way to use any of these.

Phil

Right!
Note to self, scoop up old microscopes for the group.
(I find them fairly often at auctions)
No idea if they are functional though, but hey, if I can find a few, I'm happy to share.

I picked up one of these:
www.radioshack.com/product/index.jsp?productId=2179604.
As posted by CBWX34.
I like it due to its using common AAA batteries. I also think that it provides noticeably more magnification than the 60 to 100X unit that I linked to and all of the others too. I got the other ones out and compared them directly (I have all of the units that I linked to). I think it cost just under $15 at a Radio Shack here locally after taxes. The one thing I question, and likely why it has batteries with more capacity, is the fact that it uses an incandescent lamp. That means it uses more power and is not as bright at the LED lamps. In this appplication it still gives enough light for the task, and is a bit more "floody" which can be an advantage, but I worry about replacing the bulb when it burns out. LEDs with a lifetime of around 40 to 50 K hours, likely will never have this problem in normal use. it is probably 30% larger and a bit heavier than the one from Ebay. This is proably a plus here, it is a bit easier to hold steady.

Anyway Fred, If you have a Radio Shack close to you, you can check online to see if they have one, and you can get something fast and cheap with lots of magnification to start checking things out. No endorsement or recommendation meant...just saying, they are available and cheap and work OK.

Phil

Have used mine for over 5 years now,,,so far so good on the bulb!

I did recently get an LED one... at first the light seemed "overpowering". But now I'm getting used to it. Just don't know about the batteries yet. I still seem to pick up things better with the old one... but that could just be a lack of time with the LED.

Either one should give excellent results... just take the time to get used to it.