Let me start by saying this: I love the Aprilia 4.5. The 5.5 is another story and has a really bad rap for breaking down. My buddy has one and hates it, always in the shop and has not hit 1k miles yet. My experience to date with the "street legal 4.5" has been FANTASTIC and I beat the crap out of the thing! Now to answer your questions.
Located: Honolulu, HI
Price: $9,300. Extra $$$ to make "street legal" which is done with 0 mods to the bike but by taking it to a state inspector who confirms that the "factory baja kit" on the bike meets DOT requirements. Extra $1,000.00 but worth it!
Miles: 2600
Maintenance: Similar to Ducati and around $200 for valve adjustment. ALL SUPERMOTO BIKES require about the same amount of maintenance because they are after all, "race ready". Much, much, much cheaper than a Duc service. And Ducati Service really sucks now that they have gone mainstream. IMHO Ducati has lost their passion and become very "corporate". Quote from Ducati North America after a chain break cracked my engine block- " Well since the dealer (AN AUTHORIZED DUCATI DEALER) threw away the broken chain we will not cover it under warranty." Here is what really set my shorts on fire, and I quote again " you bought the bike, its your problem". Wow less than 2k miles and 2 months old with a cracked engine block from a chain snap. Short version- State farm kicked up for the $4,000.00 repair and did not raise the rate. Average waiting time from Ducati for FAULTY SPEEDOS AND BLINKERS- 4 MONTHS. Thats right, 4 months. I guess I was not the only one having problems
I love my Ducatis, I just dont like the company any longer.
Motor life: As strong as this bike is I really don't see very many problems in the future. It is very difficult to really push the bike to its limits on the street without going to jail. Just like any bike, if you beat the crap out of it on the track every weekend you have to repair and replace things.
Reply to Sean post about dragging hard parts on the Ducati MS4: What I meant without going into to much detail was this- The MS4 has an Alan head bolts which attach the exhaust cans. The moment the bolt touches the ground you are at the edge of the tire, period. People who drag their knee never really know where the edge of the tire is. The reason for dragging the knee is because if you lose traction hopefully the knee will act as a 3rd leg and keep you from eating it by kicking you back up onto the contact patch. On the MS4 you can save a lot of "time" and stress by using this bolt as a warning sign that you are indeed at the edge of the tire.
But Sean gets paid to ride bikes and I do not. This means he knows a hell of a lot more than I do. This is just my humble opinion.
Ride the Aprilia 4.5 SXV, it will speak for itself.