I agree with most of the statements in the original post but the follow-on post that makes the argument that "the details of the deal don't matter" is both a bad take and incorrect on the face of it, given how deep the geopolitical implications and attendant backroom wrangling goes into even fairly simplistic weapons transfers, let alone cutting edge tech with wide ranging NATSEC implications.

As has been pointed out, asking to buy something in the same fashion everyone else has, with the same training and support as everyone else has received is one thing. If after you have been approved through the same process as everyone else, you decide that you require all the tools, training, software and engineering background information necessary to modify or potentially build one of them on your own; that is something else. If it were available at all it would not be available at the same price, the price both monetarily and otherwise would be massively higher. It is at a minimum the difference between buying a Honda and buying a Honda dealership.

Also given that the Patriot Missile System is a part of the US BMD umbrella, and things related to strategic strikes at best and nuclear war at worst tend to be held quite "close to the vest" it seems logical that the details of the inner-workings of the Patriot Missile system might not be available to anyone at any price. AFAICT the only example of tech transfer around the Patriot is the integration of the Rafael Skyceptor Missile into the system and that was primarily transfering information into US hands not out of them.

If you didn't know or understand any of that, that is one thing as Turkey/Western relations is a pretty deep rabbithole, especially post Erdo and no one will fault you for that. If you were deliberately trying to conceal information (which seems less likely on a reread) that makes Turkey look less like the victim and get them more sympathy after they way overreached in their relationship with the US and then decided to play a little "fuck around and find out" by buying S400s from Russia, than that would be something else and something worse. Turkey has decided to play hardball with everyone all the time and that is certainly fair and valid for an independent nation, they just shouldn't be surprised if people want to take their ball and go home, and tell others not to bother with them if they are going to be like that...

Sidenote: the way reedit rearranges comments over time based on votes makes it much harder to keep track of deeper conversations with more branches like this one...