You can change your name, but other than that there's not really much you can do. You see all your player's information is tied to your steamid, so you'd need to buy a new account for a new steamid. You can try asking management to reset your in-game character, but I doubt they'd do it without a good reason.
I think if you want a fresh start because you're bored of having everything and having lots of money, the request might be granted. But if its just because you're broke and want a easy 100k again, thats not going to work =P