Better to take some $20 scrappy mountain bikes that no one would want - and keep those Suburbans for yourselves locked away at home for nice summer evening rides with your sweetie. They are nice riding bikes (as long as terrain is reasonably level) and they are nice looking too.
I don't know that they are worth appreciably more as a matched set, unless they're consecutive serial numbers. I would estimate their value at about a couple hundred dollars, if sold together or separately.
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- Auchen