what to do with old bricks? and cheaper alternative to a skip?

Freecycle for everything.

Wood for burning, metal - they'll be like a pack of dogs for, then bricks and the rest for rubble/hardcore use.

 

you could use a couple as wheel chocks

 

Try Fletchers Timberyard in Spondon, they are also an architectural salvage yard, I'm sure they'd either buy them off you, or take them off your hands FOC.