I know you have a Mahindra but the 15 series is basically the same as some of the Cub Cadet line made by Mitsubishi. You’ll find that the Mitsubishi parts are not cheap but none of the manufacturers give their parts away. I have a Cub 7234 and I believe the 2615 is what my 23HP model grew into. My local NAPA dealer put in the Mitsub. Part numbers and he came right up with NAPA oil, fuel, and hydraulic filters which are made by Wix. I bought an oil filter, about $7 from him but the Hydraulic filter was more expensive than I could buy an OEM filter for. I was at a local Mahindra dealer’s Open House last Saturday and one of the Mahindra Reps was there. I asked if Mahindra had done any particular improvements to the Mitsubishi line and he said they had tried to improve some of the specs, i.e. lift ability, and some features, although he didn’t elaborate. I then asked about the high price of the Mit. Parts and asked if Mahindra was producing the parts or if they were just a pass through from Mitsubishi. He said they were just a pass through, so I suspect you’ll find the filters, etc. aren’t cheap. Read some of the back posts on filter cross reference and you’ll find more info. You’ll find that many people will only use OEM regardless of price and others use whatever is easiest, cheapest, etc. If you search on posts under my user name I had some posts for my Cub on filters back in ’03 and ’04 I believe. You also might want to review Cub posts as well as Mahindra as many are the same as the Cub line.