I would share you for hotel compare rate, please see below between The Grand Centre Point Terminal 21 with The Eastin Tan Hotel at Chiangmai.
Rate from Eastin Tan Hotel quite a lot cheaper and location are very good there in Chiangmai, just 100 meters walk to shopping mall and 100 meters walk to dinning & night activities area of Chiangmai.
Cost for Thai airway domestic from BKK (new airport) to Chiangmai (CNX) is about 70-100US depending on time and how long we book.
Eastin presentation in attached.