Is there at least seats available? As shouldn't public transport too be market clearing. So price should be high enough that there is always empty room in busses and the busses fully pay for themselves.

Usually yeah. London has buses every 10 mins on most routes. It can get very crowded at rush hour or school run time though. Several groups (OAPs, kids, disabled people...) get discounted or free bus passes which I wouldn't want to change.

Don't get me wrong - London public transport is fantastic. Extensive, frequent, convenient, and multi-modal. But the pricing is quite static so that people who use it for short inner-city journeys lose out a bit.

How large is the family?