pneumatic die grinders-- cheap v quality?

Hi!

I do marble carving; started somewhat recently. I've used chisels so far, but I really need to look at rotary for undercuts and delicate areas.

I'm considering foredoms, but, air die grinders appeal-- buy a compressor, which I need for many things anyway , and then plop $20- $100 for a pneumatic die grinder. They're also higher-rpm, possibly a benefit though overheating can be as much a worry at high rpm as chatter may be at low.

For both I worry about dust. Marble... seems harder than mild steel, when I accidentally forged some mild steel chisels they mushroomed over instantly; but is rather softer than tool steel. So the case may be made that some parts in the die grinder are going to abrade anyway so I should get cheap and recyclable grinders?

This varies categorically. I don't buy dirt-cheap bits for example, the steel quality and grinding precision is pitiful; a mid- range I find sufficient value for my needs. I do buy cheap ear protection, gloves, some lifting equipment-- sometimes the difference between name brand and brand X is only that, and the products are identical.

So where do die grinders fall? What brands do you like? If I might burn through bearings; are some better shielded for longer lifespan --enough so, that $/hour used is lower? Harbor freight? Random ebay powersellers? Another issue, beyond bearing slop, is air consumption (also a result of machining tolerance). My compressor does 8cfm, theoretically, at

thanks!! -Bernard