I would try to revive the lost art of "haggling".
Negotiate separately, start with the black one first then try the bundle method. Like the american pickers do.
Not knowing what your plans are for them makes it hard to advise on the subject.
Apparently they want rid of them and done nothing to make them more appealing.
If you are looking to Totally restore to show quality I would move on.
Good luck finding a "Vintage" project though, The good deals are all but gone.
As far as "Doodle bugs" being "nothing special " that is true. But for me, one that never
got one as a kid, they look exactly like what my memories are of a mini bike.
Keep in mind I'm not a collector, just trying to complete my bucket list.
You asked, so I'm gonna step out on a limb and say I would start out with 80 bucks on the black one.