Bitcoin Ballin Out of Control

When will it end? I keep getting paid in BTC and after a day holding it, BTC jumps up another $1,000 and I say to myself "It can't go any higher than this." So I sell my bitcoin and a day later: Ah phux :( What I'm thinking is maybe I should setup a buy order for some small price. Let's say January comes along and BOOM – Crash. Then I get all the coins and wait a long time this time. BUT: it could keep going to $100,000 and I'd be like "I could have had it all"