I had a business partner tell me once, if people are going to write a check, they will write one up to $100 without thinking twice. I priced my software at $99.
Especially in the B2B world. I have a simple device I sell to industrial users for under $150. A few months ago I had a request for a customized version. It required that I change two lines of code. I did that, added $250 to the price and it was sold with no questions asked.
/me kicks himself for likely leaving money on the table :-(
