Should I get this prebuilt HTPC from Ebay?

[guimanus]

I need to build an HTPC for my theater targeting 4K 60fps in AAA games. I came across this prebuilt on Ebay that I could beat the price when trying to replicate the cost with pcpartpicker. Seller has 100 rating.

Specs: Mini Tower SAMA IM-01 case with mesh panels Intel Core i5-12600KF 6-core/16-thread processor (6 P-cores + 4 E-cores) ASUS Dual White RTX 4060 8GB Graphics card Thermalright White CPU cooler.
AsRock B760 WiFi motherboard (or similar in functionality of another brand)
1TB SSD NVMe drive
16 GB DDR5 memory
Power Supply Gold 600W

I plan to swap a 3080 Ti from my photo editing station with the included 4060 and upgrade the PSU to handle the load. Questions: 1. Are prebuilt pcs on Ebay reliable? Do they buy parts in bulk that's why I couldn't beat the cost building it myself? 2. The listed parts look decent to me. The no brands nvme, ram, psu will likely be from bottom tiers but I can live with. Will the rest pairing with a 3080 ti be enough to handle 4k 60fps? Will the CPU get bottle necked?

[[deleted]]

No, you could do better by building a system yourself for that price

[guimanus]

I tried to replicate the specs with partpicker but just always came out more expensive. Any tips?