I probably only have about $80 in my 50 hr. service. That includes buying a 5 gal bucket of hydraulic fluid, engine oil filter, hydraulic oil filter, and a tube a grease. I don't recall seeing the fuel filter as a 50 hr. requirement. If I had I would have bought one.
I also bought a hand pump at TSC for the hydr. fluid. I bought this stuff in the fall expecting to hit the 50 hr. mark, but I am still about 15 hrs. shy of it. I did go ahead and change the engine oil and filter and lubed every fitting. I also power washed the mower deck top and bottom, and greased every fitting on it too.
I don't know what the dealer would have charged to do the 50 hr. service, but I'm sure in my area it would not have been cheap. They are the only real Deere dealership in my county and they charge full retail on everything.