Is what I'm thinking of doing really stupid? 😅😅

I've never built a pc before and bought a pretty expensive Alienware prebuilt like 5 years ago, now I am thinking about building my own because my prebuilt is bluescreening a lot and I've done everything under the sun to fix it and I think my ssd is probably not working correctly and the computer is out of warranty. However, I am trying to keep the price down this time and think I might be able to reuse a couple parts and sell some stuff I don't need.

Buy:

Ryzen 7 9850X3D at $489.00

Thermalright Phantom Spirit 120 SE CPU cooler at $35.90

Gigabyte B850 AORUS ELITE WIFI7 ATX AM5 Motherboard at 209.99

Samsung 990 Pro 2 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive at $389.99

Lian Li Vector V100R ATX Mid Tower Case at $74.99 (I think it comes with fans so I don't need to buy those)

Reuse:

RTX 3090

Whatever Ram I have (I have no clue what I have currently) assuming it is DDR5 otherwise I will have to spend $388.97

And reuse whatever PSU I have or upgrade if I need to.

Sell:

A laptop with a GTX 1070 and i7-8750H and 16GB DDR4 for as much as I can get.

Total I will buy if everything goes well will be $1199.87. I will keep using my 3090 and try my luck at getting a 6070ti or 6080 at MSRP when it eventually comes out which is why I am thinking about getting the 9850X3D after which I will sell the 3090.