One year ago, my builder and I agreed that the final payment owed by us was $14,900. He was to finish the project by the end of May. Instead, it dragged on and was finally finished in March. He never made deadlines, and never sent any notice of changes in costs -- no change orders. He presented me with a bill for $34,000 last month, saying that costs had gone up in the ensuing year. I said I would only pay what we agreed, and sent him a check. He is now threatening a mechanics lien on our property by the end of this week if we don't pay up.