What is an overstock?  

A first over piston?  A new bike (last years model) being sold cheap?

A first over piston costs about $100 and can be gotten on the internet from Ron Ayers or Bike Bandit or from your local Suzuki dealer.

There ARE no last years bikes -- S40 is allocated 2-3 each spring to each dealer and they last like 2-3 weeks and are GONE (here in the USA anyway).

Suzuki has created a scarcity situation on the bikes on purpose to keep the selling price artificially high at around 5,000 bucks.   When supply was generous the selling price was thousands lower, so they don't do that any more - it cuts into the sales of larger more expensive bikes.