It’s probably a general assumption that Malaysia being slightly more developed than Thailand, would be more expensive as far as tourism is concerned. Even myself, being Malaysian, assumed the same. After all, it is common for locals from Kuala Lumpur and other bigger cities to do their shopping 400 km away at Thailand borders in Kelantan or Perlis, knowing bargains are better there.
This discussion thread at bootsnall.com reveals that tourists themselves find this general perception not quite true. One strong and reasonable explanation for this is; Thailand being more touristy has a more mature and larger tourism industry; which finds ways to suck out the $$$ from visitors (read tourist traps).
Since visitors normally would prefer less touristy places, and naturally they would also prefer cheaper destinations, this could result in a major improvement in Malaysian tourism statistics. A few years down the road, Malaysia could be as expensive, if not more. Honestly, I hope Malaysia would be honost enough to not rip people off if it does get to this stage.
Stumble it!