A:AnswerI would hold off on purchasing any external drive for the ps5. Sony has said that the mvme will be the only way to play ps5 games. Right now it is believed that you can use an external drive for storage only (not to actually play the games), or use one to play ps4 games, but this has not been confirmed by sony.
A:AnswerIt would be in the form of a gift card and or store credit, I would search Best Buy's trade in service and get a quote and estimate to see how much of a credit you will get for your PS4.
A:AnswerI think they are in waves of 3's, the first 3 million sold out, instead of selling all of them at once, Sony wanted to see how popular/hot they would be and how fast they would sell, they anticipated they would sell out quickly but not this fast so before selling the next wave of 3 million they are making mass production of the consoles and I believe should start making them available to vendors/retailers next Wednesday I believe. I was told that Sony would have more consoles available either Wednesday the day the Xbox Series X&S can be pre-ordered or the day before on that Tuesday.
A:AnswerYes, it is a 4k bluray capable disc drive in the disc version only. Also, the console can support even higher resolutions than 4k so it may be updated in the future if the format increases again in resolution.