06 3500 6-speed 123000 very hard miles..... bearings for 1st 2nd and reverse are bad... wondering about replacing another set of bearings... . they tell me the bearings only come with the counter shaft they are on which is 1200 bucks..... the current bearings seem to be in good shape am trying to determine would it be worth it to change the shaft or run the original one... and what does a new transmission cost and what kinda warranty could I expect with that.