Here is a link for the filter in Question: It doesn't look all that expensive at $18.14 B2150 filter lookup You can put your part numbers in and find out the price. This Kubota parts from Tractorsmart.
Could be worse- I just paid $52.42 for HST filter for my L3710 (Gold Country Kubota) , seems I did'nt buy tractor from them
so they gave me the ripoff price /forums/images/graemlins/mad.gif
Price at TractorSmart $47.65 same filter, also checked other filter prices --all were less.
Now $5 difference is no big deal - but it's just because tractor wasn't bought there they stick ya that pisses me off /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif
Seems to me when I bought the same B2150 in 1991 the hydraulic filter at that time was over $37.00 , So $18.14 sounds cheap to me even if You add shipping it isn't that bad in my opinion.