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

Lowes set sells for about $30.
Woodcraft has sets for about $50 up to $400.
I have also seen carbide tip sets for about $130.

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

I will be using the bits in a chuck in the tailstock of my lathe
cutting into various kinds of wood.

Thanks for any info,
Ted