How much should a probate of a will cost? Involves changing land & minerals name from husband to wife.

It will be several thousand dollars if it is a "vanilla" probate as you have presented.  This would mean there is a will and it only controls real estate and nothing else.  That would be unusual, but possible.  There are several steps that include notifying all his heirs at law--usually his children whether they inherit anything or not.  Then publishing for creditors has to occur.  If there are any, that is additonal time and expense.  You dont say what county and this affects fees as well.  In some counties an attorney may have to wait for hours to have the case called.  Lawyers typically bill this by the hour.  Also this is affected by the use of paralegals whose lower hourly rate generally lowers the cost of the document preparation, compared with the attorney that does all of the work himself.  So the bottom line is how many hours will it take and that is driven by your situation.  Good luck to you.