Young's Painting Young Cho Provided bid for painting work, wanted cash first, then would not sign a contract for the work Falls Church Virginia

Mr. Cho quoted me $950 for painting my garage. He was the low bid of 3. He asked if i had cash right then and there. I told him i would get back to him. Later the same day, i provided him a contract to do the work. Having used his firm in the past, i knew that he often asked for more money than agreed at end of job, saying he did extra work.  So i put that any cost adds would have to be approved in writing first.  He would not sign the contract, and claimed he was busy for the next two months and did not want to do my job.  I have his written quote.  I don't know if this is illegal or not, but it is certainly unethical, and i will not be using his firm ever again.