Currently own a Yamaha RBX270L and i am currently looking for a new bass.

Budget is around £500 and i'm looking for a low and crisp tone, much like Steve Harris.

Any ideas?
since Steve Harris used P-basses, that would be an excellent choice. He also used flat wound strings, if it helps. He has a sig set, but I dunno who makes them.
"We are, each of us, angels with but one wing, and only by embracing one another may we fly."- Luciano de Crescenzo

Makes you feel good inside, don't it?