There are a total of three hotels on Tsing Yi, all in same complex, and not convenient since there's a walk from airport buses to the properties, or require a shuttle from the Airport Express train.

Not many hotels in Tsuen Wan, and most are old or small, with the exception of the L'Hotel. The Airbus A31 goes directly there, but it takes a grand tour or the Kwai Fong, Kwai Hing and Tsuen Wan area before getting to that last stop. You'll get to Kowloon proper faster than that, and all you save is two US bucks on the bus fare - HK$18.9 on A31 vs $33 on the A21. The Panda is the only other major hotel in Tsuen Wan - a few stops earlier on the A31, but still require a short walk to hotel from bus stop.

Tsing Yi or Tsuen Wan only makes sense if taking a taxi (saving a few dollars and a few minutes), but that also cuts into your savings. Otherwise, look for options in Kowloon or even HK Island instead.