You're a plumber? WOW! A PVC drain pipe broke under my tub/shower. My toilet backs up and using any water in the house results in an inch or two of standing water on my floor. What would you charge to fix it?

Yikes! It sounds like you have two separate problems. ***Problem 1*** The clogged sewer main can usually be cleared for $200-$250...assuming that it is a clog and not broken pipe. If it's broken pipe, hopefully it's not under a concrete slab. Best would be if it's in the yard. In any case, unless a single break can be detected and dug up, thousands of dollars to replace either the pipe under the house or the pipe running from the house to the sewer. ***Problem 2*** The pipe under your tub/shower should be a 2-inch pipe (which is why THAT pipe being broken is almost certainly not causing your toilet to back up), and how much work it is to fix depends on where the pipe is located. Under the house, with a crawl-space under the house giving access to the pipe? Or: a second-floor shower with access to the pipe by cutting into the ceiling? Under 1,000 dollars. If access is VERY EASY, maybe $150-$250. It depends on how much work is needed to fix it. ON THE OTHER HAND, if the pipe is under a concrete slab, then there's jack hammering, possibly the need to remove and re-install the tub, etc. Price depends on the situation, but at least $1,000 dollars and more likely $2,000 and up.