P1Million is roughly equal to $20,000 ; this is the real reason that the buses are selling.
Manila traffic jams make getting out of the Holland Tunnel at 5PM Friday look like a walk in the park. So being able to go fast is not a requirement. Since everyone is going about the same speed, a more powerful engine doesn't buy you much. But $20K USD in the pocket is a big deal, especially in a country where taxes are for the most part, considered optional.
Interesting that America no longer deserves mention alongside Japan and Europe in this industry...