Somethin's not right with the math here... I'd have to guess that the $250 charge is for the dealer doing the maintainance work - drain, clean sump screen, change charge filter, replace inline filter and refill. Yes?
All you would do show up with the tractor - or does that include pickup and return of the tractor to your place?
If delivery is part of the equation - your dealer is losing money!
Hydraulic oil is around $60/5 gallon pail. You need around 10 gallons - eHydro transmission.
2 filters @ $55. That comes up to about $175.00 more or less.
Again, if the dealer is doing the work or if that includes tractor delivery... it's not all that bad a deal at all - and if they're delivering your tractor - get on the phone right now... 'cause he's losing money!!!
Low-viscosity hydraulic oil in my area is about $90 for a five gallon container & that is at multiple dealers. Roughly $70 for a hydraulic filter, so it's coming up about right.