Current non-discounted Disney prices for single day water park tickets are $49 Adult, $41 child. You would need 3 Adult, 1 Child = $188 + 6.5% tax = Total 200.22.
You didn't say what the CL tickets would cost. But as others have posted, there is no way to know if the CL tickets were already used, therefore worthless. CL does not enjoy a good reputation as a source for legitimate WDW tickets.
For $55+tax per ticket, you could add water parks/DisneyQuest to your regular park tickets, and you would receive as many entries as there are days on your park tickets. In other words, you would have multiple visits, plus the opportunity to play at DisneyQuest.
That's the safe bet.