You cynic! You forgot the alternative option of:
Ordering new thermal Arctic Silver paste: 24hr
Finding out the PS4 has weird little screws that need a special screwdriver you don't have so ordering some of these too or popping down to Maplins if you have one: 24 hrs/2 hrs
Disassembling the PS4: 4 hours, removing old crud, applying new compound 20-40 mins depending on how carefully you do it
Reassembly: 10 hours as you've lost a few bits and forgotten how to do it so look it up on Youtube
All ready to play... except you need a new HDMI cable and telly.
Yeah, console gaming is really getting a lot like the PC these days.