9955x3d with rtx 5080 vs 14900k with rtx 4090

Okay so I am in the market for a new laptop. Currently have a 13620h i7 with rtx 4050. It's been decent but I want something with more power, would like to get into running AI locally, playing games at 4k 120fps, some video editing/upscaling. I saw an MSI raider 18 with the 9955x3d and 5080 comes with 64gb RAM and a UHD+ screen. It's on eBay for 1900 plus tax. I've been chatting with someone on marketplace looking for a quick sale on a scar 18 with 14900k i9 and rtx 4090 also come with 64gb RAM. He only wants 1675. I'm having trouble deciding as they both seem like great deals on laptops that will be more than powerful enough for me I'm sure. Thanks in advance for the advice.