I have seen Forstner bits sell for a wide variety of prices:

Lowes set sells for about $30.

What should I look for? Is carbide better or is high speed steel OK?
Is it hard to sharpen the non carbide bits?

Like all things, you get what you pay for, and more expensive stuff is
usually better.

Having said that, I have the $30 set from Lowe's, and I have used most of
the bits extensively. They make nice holes, and I'm glad to have them.

The only one I've replaced so far is one I ruined by boring through several
sheets of 60 grit sandpaper. I tried to sharpen it, and never got anywhere
good.

I replaced that one with a Freud bit, also from Lowe's. The one bit cost
almost as much as the entire set. I must say that there is a *huge*
difference in performance. It cuts about four times more easily, and is
less likely to clog up.

Whether you'd get even more performance by stepping up from Freud, I don't
know. It probably really depends on how much cutting you plan to do with
the things, in what kind of woods. I've bored probably into the hundreds
of holes with my cheap $30 set, and I haven't felt the need to replace
them, even after seeing the performance difference with a better quality
bit. I will eventually replace them, but it's not urgent. The cheap bits
work, and make nice holes, they just take much longer to cut.

--
Michael McIntyre ---- Silvan
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/