if you weld for a living, you should get a production tool. You're cheating yourself if you get anything less. Spend the $$$, or watch ebay and spend less $$$, but it will still usually be more than $50, unless you get very lucky.
I like Sioux (US Made only), IR (industrial production series, such as the G model numbers, or the older cyclone T & H model numbers), Aro (made by IR), French-made Chicago Pneumatic/Georges Renault, Atlas-Copco, Dynabrade, Henry, TC service, Dotco, and 3M. All great tools. Get whichever meets your specs at the price, and be happy. Some go for more than others, but the build quality is very similar between all of them. I like the Atlas-Copco full-size die grinders the best because of their spindle suspension. Really reduces chatter when using carbide burs. Don't be fooled by the low-end IR, CP, or Sioux. Not the same thing at all.
Here are the pics of my grinder drawers. Yeah, I'm a bit obsessed