The price of 4k discs will mean very little compared to the price of a quality TV set up to display the potential of the discs properly. At the very least you'll want an OLED panel tv, a budget model would be something from LG like the C2 or older C1. The Sony A95K and Samsung S95B are the big dog tv's with the newer tech QD-OLED panels. You're going down a long road of research on how much to spend on a setup, so back to my main point spending $10 or $20 here or there on a disc is really a non issue compared to the decision of spending $1k-$3k on a tv. In addition to that you'll need a disc player so Xbox Series X, PS5, or standalone player for non-gamers is another $500. Discs are always at their cheapest around black friday which just ended. Brand new titles were selling for $10 or less. It's the best time of the year to start a collection.