The center of Da Lat is mostly accommodations, with a huge variety in quality. There are places from $5 to $200 per night, so you should be able to find anything you want. The backpacker area is near the market where the going rate is $10-12 a night, but there is a huge variation in quality. Make sure you check out several different hotels as price doesn’t dictate the quality of rooms.
We headed downhill on Đường 3 Tháng 2 from the market with a Canadian couple. After viewing rooms in 4 places we found that there was little variation in prices, until we found a great little place that charged $6 a night. It was difficult to figure out the price due to their total lack of English. Finally they called a friend who spoke English and had me speak to them. The room was equivalent to the $10/night rooms in hotels surrounding it and had good Internet access.