I always brought 2k broads and always left with well over 1k so you could do it easily with only 1k. I always had loads in my bank and didn't really care. Yes you can log out between waves. Let's say you're midway on wave 33 but you have to leave you comp. By pressing logout once (actually clicking "return to lobby" or whatever the other one is) you'll be able to finish your wave and the game will automatically log you out when you kill the last monster. When you log back in, you'll be at the start of wave 34. Alternatively, if you're really desperate to log out you can close runescape though you should be aware that if you are still in combat, your character will continue to fight (alright if you have pro prayers on and a lot of pray, not if you're being attacked by more than 1 attack style. In this case, when you log back in, you'll be at the start of wave 33 again, having to redo all the progress you had made in that wave. When you log back in does the wave start right away, I remember being able to heal up and such? It gives you a few seconds to prepare for the wave when you log back in.