fuel line leak in w124

[JasonOne]

I know this is a tech problem that I should take to the indy MBZ and/or Euro mechanic but I thought I'd post here to make sure.
Initially I was told it was my fuel pumps but since they are working fine it cant be them. In fact this was shown to be the case by a mechanic who was steering me in the right direction, I think. Recently I have had the car up on lifts, three times in fact. The last time was at a muffler shop where we left it running. The leak at the main fuel hose is quite evident. Obviously I was unable to have any muffler work done at the time. As of today I'm past my CA emissions extension and will be paying more to DMV when I finally get there with a smog certificate. Then I'll be good for two years. I've replaced the 02 sensor and the oil and other fluids and filters. I've had the entire auto inspected by a number of seperate MBZ master shops. Two were full of crap and two were very helpful. Thankfully I have not paid for these going over checks. I was quoted $300 for an inspection and fix of the entire fuel line system. Does this seem reasonable? Or could I just have a loose clamp or worn hose on the main line? Seems it could be coming from the the top of the main hose. The leaking fuel is dripping right down along the hose. I suspect it may be a simple fix. Any suggestions? I have been putting money into this car and will be putting more in right away. The motor is running very clean and the cat seems to be converting. The mufflers are done (originals) at 110K miles. I need to do the muffler change (dynomax cans) right away to get the emissions machine to read the levels. In order to do that the leak has to be fixed.
I apologize for the long post. This forum is the most helpful.
Thank you,
Jason