Well, the virtual pinball wasn't cheap, but to have real pinball machines is crazy. They need proper maintainance if you want to keep them functional. Thats specialist work and it needs spare parts, like new rubber bands and such.
Despite all I said, I would recommend Zen Pinball 2 all the time. I tried a few other, but they were not as good. You can try it yourself - the actuall program is free and comes with one free table.