Myself, only owning one, I couldn't give you an idea of the averages or anything. I think Dave would be able to provide a better answer being a dealer. All I can say is from my own, the work itself on just the lines shouldn't be much. An hour for the feed line and 15 or 20 minutes for the return perhaps...
The only hard hoses to replace are the ones going to the tank. You need to remove the left rear wheel and drop the tank down just a little to get to those connections. Takes about 2 hours to do all of the lines. Easy enough work, except wrestling that big tire/wheel. Replacing the hoses is a must. Sometimes they last a couple of years, some times a couple of months. The new hoses are great and we have never seen a failure once replaced. One error many folks make is to just replace the easiest to reach hoses. Do them all.
While you are working on your tractor, make certain the power-steering hydraulic hose is positioned away from the starter positive terminal. Zip-tie it or do whatever to get some clearance there.
The TSB for the hoses allows the dealer 0.92 hours to do the repair. Real time, about double that. That's why dealers are not so anxious to fill the shop with warranty work.
Thanks so much. I talked to the dealer before I posted my question. He said it would not be covered under warranty. When I asked him if he knew the approx shop time to do the work he said probably 5hrs ish. I thought that sounded like a lot which is why I posted the question here. I'm not saying he was dishonest- it sounded like he was guessing somewhat on the time. He also said If I'm not having issues with it why not just leave as is and keep an eye on things. The tractor is 5 years old with what I'm guessing are the original lines.
Another issue- maybe related. So, after sitting for 3 days I went out to the barn, turned the key and the tractor fired up no problem. Ran it for about 45 minutes straight then shut it off to do some shoveling by hand. Hopped back on it 10 minutes later and it won't start now. Cranks over but doesn't start. Getting frustrated. Could all this be fuel line related or likely something else?
Around here we have a saying, "fix what you know is wrong first", then look for the less likely culprits if all is not fixed. You might have an electrical issue with the start solenoid, but I'd get the fuel lines changed out anyway first.