[TStodden]

I would suggest on getting a bank because:

1) Provide a safe place to hold money
2) Decrease PKing/Hunting
3) Have power to be used elsewhere on the server. (assumed that there's more than 1 bank on the server)
4) Don't have to rely on a friend to hold your cash while you PK others.

The downsides would be:

1) Increased PKing around the entrance & exits.
2) A target for hacking, bugs (which mean that the programmers didn't do a good job making the script), & glitches (depending on how the system was programmed).
3) Potentially easy to abuse.

I do have a basic banking script & levels made, but I will admit that the transaction system is a bit laggy & somewhat primitive, but fairly solid construction. Feel free to contact me if you would like a copy or if there's enough support on a free bank, I might post it here.