Hi , You'll be taking a chance on junk getting in there and ruining the whole assembly. I personally don't know the life expectancy on the entire oem assembly but do know that I am getting over 4000 hrs out of my first ones on this 2011, on the 2005 which were fine when sold at over 4200 hrs ( my current 2011 rtv xt that just rolled over on 4000 hrs last week). They are still fine as far as I know . Thanks chiefly to the super duty Peanut stick stoppers.
I understand what you are thinking - if an entire assembly is just a little more complete than rubber boots alone, and ready to put on why fool with boot replacement? I think the boots themselves I put on the 05 when I sold it in August of 2011 were not cheap . The ones that came with it new though did last 6 years. I also noticed cracks down in the ribs when I was getting ready to sell it- if I remember right, so replaced them. It's important to keep dried mud from caking up around them too. Sometimes the stick stoppers can hide that, but the worst place is right there by the A arm where it meets the frame. mud just loves to hide and dry there and do the rub a dub dub to the boots.
If I knew the whole assembly could be had for almost the price of the boots alone, I would maybe lean that way , but I just don't know their long term track record........ collie