Or.... BR Shock Adjusters for the '13
Or consider BR's Shock Spring Pre-Load Adjuster Kit, there's another thread going on right now about them. I too doubt your shocks are already bad, but the adjusters do allow you tweak your stock shocks for a lot less than the Elka's or Fox's.
and my two cents.........
I also have a '13 STL. I am not a spirited rider and most of my riding is 2 up. In my opinion, the stock suspension on the '13s were marginal to say the least,brand new. I now have 36K on mine and the original setup was sacked. Just 2 weeks ago I installed a new set of Elka stage 2 front and back, and what a difference. Now the tires just stay on the ground. Period! And my wife's back has fallen in love with that rear unit.
I would suggest this. With that low mileage, I don't think your suspension is shot. If it really bothers you then by all means get the fronts. You will fall in love with the bike all over again.