There is a lot of money that you can spend on model railways, but thats only if you want to.....
For example I was looking at motors, wheels, axles, And the price came to near £80, and I thought to myself "cor I'm going to need a job", but if you compare it to video gaming, that is dead cheap, console-£200-400 games-£30-50. So maybe model railway isn't that expensive at all, but in the end, it's your wonga and you can do what you wish.