Tough question...
1.8 long blocks are relatively rare, which pushes the price up, but, they are also not in high demand, which pulls the price down.
Realistically speaking though - I doubt, even giving it away, you could find any takers - anyone with a Sidekick Sport needing an engine will either be scrapping the vehicle, or a Suzuki enthusiast looking to do a 2.0 or 2.3 swap just as you are.
Put it up on Craig's list, what have you got to lose - you might find the one Suzuki enthusiast who wants a "period correct" classic ...