Is it a Boatmate trailer? The cost to add a second axle is cost prohibitive. IMO, you may be able to find someone who wants to swap with you and some $.

The singles are easier to maneuver around in a garage. Some Stroker owner may have a tight storage area.

Call Jerry at Boatmate for the current tandem pricing.

I wouldn't avoid buying the boat just because of the trailer, if it is what you want and in good shape.