I have a Stihl FS80 trimmer, and a BG55 blower (homeowner). As is my usual routine I went to the dealer today to by the following: 2 sparkplugs, 2 air filters, 2 fuel filters, and 2 pints of gas/oil mix. Total - $27.70. I'm starting to wonder I could just not to do any of the above, and with the money saved at the end of 10 yrs, buy a new one. Is it worth it to do so much preventative maintenance? The machines get at least 1 hour of use a week.