i was for some reason able to buy gobekli tepe

[mint hazel]

i was able to buy it with ideas, even though i didn't buy it with logits

[sullen patrol]

I ran into this same issue. I had enough ideas to purchase it, so I did. It even showed up in the garden. But in the tree, it still looked like the outline shown in the picture above. And it also seemed to increase the output of the Stone Age generator as well.

After all of that, I saw it in the logit store, and I bought it there, and it gained a solid look in the tech tree.

[mighty hazel]

wait you bought it in the logit store

idiot

idiot

idiot

[warm plinth]

I have the same issue

[oak barn]

It's called being fair and undoing bug abuse