Around how much will it cost to replace my main water line?

I have a pinhole leak in my water main coming in from the curbside water meter. Probably 3/4 to 1 inch diameter...about 40-50 feet long. I've already trenched out about 1/2 to 2/3 the length, but tired of messing with it myself. Pipe is REALLY corroded, so definitely needs to be replaced. Can anyone give me a ballpark figure on how much it will cost to have a plumber come in and fix it? Thanks.