Super City Skyport Building Set - buy it now!

I got curious about whether the Super City set of my last post had been available in the US. So I had a look on US ebay - and guess what? The Super City Skyport Building Set is for sale right now - 2 sets, mint in box, buy it now - and seven have already sold. Sounds like old store stock. It's described as Marx Toys 6548 - interesting, when mine says Ideal Toy Corporation. Was there a link between Ideal and Marx, I wonder?
I'd love to hear if any of you buy a set!