How much immigration attorneys charge on average for M-1 visa or for F-1 visa?

There is no average in the practice of law as each counsel charges a certain amount of fees based on her/his experienced/time required/skill/expertise and other unique case factors which affect such honorarium.

Call a few attorneys in your area for an estimate and calculate the average.

I agree with my colleague. There are no set attorney's fee. Call attorneys for fees, some attorneys post their fee schedule on their website.

Attorney fees vary. It is best for you to contact attorneys in your area. A fee an attorney quotes you is based not only on the facts of your case, but the complexity of the matter and your particular situation. The type of visa you wish to obtain s only the beginning to the inquiry of how the attorney will handle your case.

You have to call a few to see how much you would pay. You don't have to just call the local ones, you may be able to pick one from this forum. There are very experienced attorneys here and also offer Skype consultation as well. Any attorney in the US who practices immigration law may be able to help you. good luck