Hi matt,
Trouble is, many 'standard' cars are also higher performance variants, and can require much more frequent oil changes - like at every 3000miles! Even my uncle's old Nissan bluebird Turbo made in 86, required oil changes every 3000 miles or 3 months - although technology has moved on, turbochargers(ing) is still very popular nowadays and its imperitive the oil is clean and changed regularly. When you come to higher performance cars, servicing costs can add up quite abit! 'bread and butter' cars you can get away with less frequent servicing so long as you know how you drive/treat the car - many many short start/stop shopping trolley school runs and the car will need more frequent servicing - longer more sustained drives would require less (sort of!)
for the OP - places will do 'quick changes' - kwik fit and charlie browns autocentres do this kinda stuff, however, becuase of the different needs for different types and kinds of cars, I suggest you look at the car you have, look up on forums specifically for it or it's manufacturer and adjust your personal scenario from there. If you have a more 'bread and butter' type car, adjust your spending on servicing on it dependant on your driving style/amount. If it's a more specialised car, adjust accordingly again.
Beware of taking to the main dealer and saying service and fix everything - always get them to quote you before doing any remedial work! a mate of mine made the mistake of dropping his 911 to Porsche and saying fix all the faults on it - he knew his car was excellently maintained, but says he fell out of his chair and $hat himself at the same time when the £600 bill he was expecting turned out to be £4500! - they had fixed every single little issue, down to replacing slightly loose screws, and interior trim bits and even stone chips!
Lastly matt, the 87 octane of US fuel - the engines are 'matched' to it via the manufacturers. I doubt very much that increasing the octane also increases longetivity of the engine's life - although I'm not a petro chemical engineer, there may be technical reasons for differences. I have to look up what's on my F150 truck, but I do remember speaking to importers and people in the know, that I didn't have to worry about the 95 RON fuel I'd be frequently filling it up with here, I didnt have to do any adjustments, all taken care of by the Engine Management Control system.
Cheers! Dennis! West London & Slough UK!