My briggs toilet tank totally cracked. Flooded my bathroom, etc. Want to replace with a newer model, have been advised by a plumber and home "experts" that it cannot be done for less than $300 since my toilet was a custom and has a 5-3/4" hole and the bolts are 12" from the wall. What does this have to do with the cost? Why cant I just buy a toilet the same size and replace where the old one is located? Is there a difference in toilets besides round vs elongated? Please advise need to replace ASAP. Thanks