When I first read Ubik I though their economy is unrealistic. How do the appliances and doors that charge for usage make sense?

It makes an interesting replacement for the warranty in the item contract. Pay the toll, and the item is kept constantly serviced. The protagonist's attack on the door also makes sense since it is considered a breach of contract.

Could also be a free to play type thing. You get the door for cheap/free, then there's a service fee for use. Hell I can imagine it with a screen and being asked to watch an ad before egress. Even better is the poor guy stuck outside his apartment while having to sit through a horny ladies in your area ad while the neighbour walks past with her kid in tow.

I can think of Kindle as a physical device that comes with ads until you pay more money. Surely there is potential in this approach for other home appliances.