Sounds like you got you for list price plus some /forums/images/graemlins/frown.gif... It cost $35.45 for the 2 1/2 gallon jug from www.tractorsmart.com plus shipping. When ever you have a pricing question, I suggest that you check there site to see how much they sell it for before going to your local dealer. They usually sell for Kubota's suggest retail price.
NH 1630 W-7308 FEL/ Kubota L4630GSTC W-LA853 FEL WQ/A-CC 2544
I checked the price there when I arrived at home, but did not know if that was the MSRP on the oil or what. All that I know that $5.15 per quart is to high, unless there is some precious metals invovled in the process.
My dealer's pricing has been the same as Tractorsmart each time I checked in the past.
Last time I got SUDT the 2.5 gallon container was a couple dollars more than half the cost of a 5 gallon container. Last time I bought a 5 gallon container I believe it was under $70, but that was last summer...