After discovering a minor but wasteful valve leak in a toilet at home, I found out that our usual plumber had just retired. So I called around and found a company called Sila that was able to send a plumber the same day. He arrived on schedule and confirmed that an inexpensive filler valve was needed and would cost about $15-$20, and that he would be able to complete the repair in 1o-15 minutes. He then quoted a price of more than $650!
I didn't hire Sila! I now have a local plumber coming later today at a very reasonable price. I'll be glad to share his contact information once they've completed the repair.