Last and (almost) best of the 1155 LGA 9th gen CPUs. If you've alredy got a decent cooler and an 1155 + 9th gen compatible board. Saves you buying an AM4 board for a 5600X (probably faster in games and definately more efficient) however 8/16 5.0 GHz CPU should last till the next gen AMD Chiplet CPUs come around…
Not sure if you need prime or not for the free delivery
If you don't have a 9th generation motherboard or want integrated graphics, the almost identical 10700K can be found a bit cheaper, and the 11700K has already been down to the mid-$400s a couple of times. 12th gen later this year may also be a big step up.