Gaspipe = straight gauge, hi-tensile steel. Most relatively modern/not garbage frames are made of butted cro-moly steel, which is much lighter and stronger. Whether that matters or not to you is up to you.
Spacing: most older road bikes have 126 or 130mm rear spacing. And if it's steel, you can just squeeze them. No big deal. The only hassle I foresee is dealing with one-piece cranks (though you can replace it with some American BB BMX cranks) and the associated pedals. And finding a seatpost.
I'd offer $20 for it, and keep looking.