Just a little background: I bought the bike used, on Oct 30, 2009, from Spykes in Lafayette Indiana, for $6955, out the door, taxes included. It was used, with 4500 miles on it. The bike had been backed into, knocked over, and fully repaired. It still looks brand new. It had, and still has a set of $800 FMF carbon fiber mufflers on it.
I put aprox $80 worth of track stand spools, fork sliders, tank pad, and frame caps on it. That's it for mods.
Shortly after I got the bike, the main wiring harness needed to be replaced, under warranty. And somewhere along the way, one of the front rotors got out of true. I suspect from being knocked over, because no one that I talked to had ever heard of a Brembo rotor going bad. For a long time, the bike was stubborn to start. But a couple bottles of Lucas Oil Fuel Injector Cleaner helped that a lot.
So... I'm not sure if the valves were ever checked. When I bought the 390 Duke, from Spykes, it was a good opertunity, to leave the 990 behind, to be serviced. I think they did an excellent job. Everything looks as it did. All the valves were in spec. That's always a good thing. The dirty air filter got replaced with a new one. The throttle bodies were cleaned. The motorcycle has been give a clean bill of health, and is as good as new inside and out.... Except he the headlight cover still has those "spider cracks" in it. So they sold a headlight assembly from a race bike, to me for $25. Pretty cool. $196.00 well spent.
Here's my $25, used headlight Assembly. Looks like new.
I have no plans to ever sell mine. The 990 SDs were so expensive when they were new. KTM was still fairly unknown back then. I'll never forget the first time I saw a new one, on the floor at S and S in New Albany Indiana. $11,999 was on the price tag. That's probably why they didn't sell a whole bunch of them. I talked to the original owner, a young guy before I bought the bike. He said he lost $6000, when he traded it for the RC8, which he didn't like as well.