New ones can be had for much cheaper! I don't want to piss anybody off but I know of dealers basically giving them to other dealers for $5K still in the crate. The dealers get a lot of incentives from Yamaha so even if the dealer cost is $6500 that isn't what the unit actually costs them. Outside of us, nobody in the general public is buying superjets and the dealers are tired of sitting on them. And even worse here in California you can't buy new superjets because of our lovely CARB rules.
Stand ups in general are so rare that you’re going to need to be willing to drive for a good deal. I know of several 2012+ in IL and MI for sale for under $6k.
In 2016 I bought my ‘13 for $7500 barely used (couldn’t even tell) that came with trailer, cover, hitch hauler, blowsion scissor stand with custom wheel dolly base, and the sj had a full wamiltons wammer mod b pipe setup, ballistic battery, rrp flat bar & controls, blowsion bilge, and a tray wedge installed with new thicker padding.
So I figure about $1300 in ski upgrades and $1100 in other accessories. But I also drove from MI to NY. Wasn’t a big deal. Made a weekend vacation out of it.