The knob to turn the main water shut off valve to my house seems to be missing and the stem where the knob sits on seems to have been broken off (judging from the ragged end). How much does it usually cost and what is entailed in fixing it with a plumber? I dont’ want to get ripped off when I call in the plumber in the next day or 2.
Some stores have handles that have a nut on it and tighten it down but might be hard to find. If you can get the name of valve you can get a new stem but you will have to turn off water outsde to install. You can take a piece of copper pipe like 1/2″ and drill a hole that size of stem and fit it and solder it to stem are drill a hole through the pipe and stem and put a small nut and bolt in it.
I assume that you have a water shut-off valve at the water meter that supplies your house. This meter is usually located out on the sidewalk in a cement box. If you feel comfortable doing so, you can shut off this valve at the meter, and work on the valve in your basement. Your best bet would be to remove the defective basement valve and install a new one.
FYI, the municipal water company is responsible for any plumbing lines/fittings up to your water meter. You are responsible for the plumbing between the meter and your house. Unless you feel real confident to replace the basement valve yourself, I’d suggest hiring a plumber. It is an easy job, and shouldn’t cost much. Such a job shouldn’t take more than 1-2 hours.