Not sure if it is the same on the 44, but my R22 also needs 25 hour changes. This is a bit of a pain, not due to the cost but the necessity of having to take it to the maintenance place every 25 hours for a 5 minute job. I enquired re the cost of the Robinson filter mod which gets rid of the 25 hour changes, but as this was £1000 or so it did not seem worth it. Like you, I don't see why I can't do it myself - I used to do 50 hour checks and oil changes on a private cat Cessna which has the same engine. I don't understand the different rules re private and public cat allowed maintenance now that the C of A is EASA.