You can use a low speed scrubber and a red and white pad (red on top white on bottom touching floor). Just make sure its not laminate of any kind. The 1$ per sq ft is a good price, and .50 for finish plus the cost of the finish. Make sure to test for wax finish before starting.
I bought a bona power scrubber last year, at first i was about .42 cents a sq ft but have come down, its quite easy to clean imo. I use the bona products but i do not apply a finish i just clean .. everyone has been very happy with the cleaning ... now i charge about .24 cents a sq foot ...
a few side notes
* i think the machine needs some modifications to it... bigger wheels for one bigger tank but of course that will make it weigh more..
* its easy to use.
* not that many people want this service