Ho Chi Minh is almost twice as expensive as Hanoi? I didn't make it to Hanoi, but everyone told me it was the more expensive of the two. HCM is really cheap everywhere you go if you just stay out of the financial sector.

Keep in mind AirBNB doesn't seem to get sites below the $15 range, and a lot of hotels that are in this range don't list on internet exchanges either. For example in Ho Chi Minh there's a few decent airconditioned hotels next to Bui Vien for $10 a night but you wont find them online. Also in Southeast Asia I've found you can rent most everywhere for 30 days at a time, which in my mind is short term when I consider all the minimum 12 month leases I had to get in the US.

Good job though, I like that you're scraping other sites. This should be good to use in conjunction with Numbeo, which has its own biases.