Get a couple of actual quotes. In my case, we were told it would cost an additional $3K to relocate the toilet, not counting ceiling repairs on the room under the bathroom. So we nixed it. YMMV

yeah, that's not in the budget...but Ill get quotes. ugh

We just added a bathroom to our basement, which involved cutting the concrete from the main drain to the new toilet and shower locations (about 7 feet away), adding the plumbing in the trench, and then pouring new concrete. Excluding any flooring or finish over the top of the new concrete, the work cost us about $1500. And we feel like our contractor is very reasonably priced.

I so want to move the toilet in our basement bathroom. Everytime I mention it to my DH (plumber) he either sighs, rolls his eyes or says "Are you going to run the jackhammer?"

I'm also very paranoid that it will compromise the foundation or other aspects of the house. Is this a reasonable concern? Or am I just being paranoid? I just think of a jackhammer in there messing with the foundation and picture all the walls and everything shaking.

My guy just used a machine that cuts the concrete, not a jackhammer. He very cleanly outlined the trench, and then was able to pry the concrete out by hand. Nothing shook. Our house is over 100 years old, and it was interesting to see what was under the concrete - including a waste pipe that had probably been leaking for years. It doesn't seem like the integrity of our foundation was harmed by cutting and patching.