Strange that a 'professional' bettor wouldn't know this...
a Unit is the average dollar amount you spend on a play (or what you normally spend on a play).
In your case, a unit would be $500 or $1000....
If it's $500 per play, and your record is 3-0 (2218.15), then your record, as reflected by units, is 3-0 (+4.44).
If you're normally betting $1000 per game, then your record, as reflected by units, is 3-0 (+2.22).
Similarly, if someone states their unit value is $100/unit, and constantly post 5 unit plays at $500 each, then their unit value is not $100, but rather $500.
If you're genuinely concerned about helping other players, then post your record in units won/lost, not dollar amount.
a dollar figure in the thousands means very little to a guy betting $10 a game, and is often misleading.