1988 300 sel coolant leak!

[Snibble]

Ok.. here is the deal. The coolant started leaking but at the time was very small amount which I though is normal. Later on, it started leaking more. I went to MB dealership and put some coolant in to the car and it didn't leak for a week. Now, the coolant is leaking from the bottom. My question is... how much would I expect a MB specialist who doesn't have to be a MB dealer tech ask for to fix this problem? I know its hard to say without knowing the exact cost, but I mean the low end and the high end(worst case scenario) cost of fixing a coolant leak. I am contemplating whether to get this fixed by a tech if the price range is at a range I can afford or wait until my father gets back and helps out. For those who don't know I am 17... so its not like its an adult asking his dad for help.

thank you