The problem with Ebay....SHIPPING
Shipping is very high & risky,I've shipped PC's all over the US (65 gamer PC's so far) & about 20% get damaged in shipping,CPU HSF pop off,GPU's get jogged out of the PCIE slot,some even ripped the PCIE slot off the mobo
I went so far as too use large foam chucks in between the GPU & CPU HSF,encapsulating the CPU HSF.It helped but FedEx & UPS are very abusive on large boxes
& the 11% of sale charge,then another 8% of Paypal charge..........
You might do better by selling the parts separately,less risk & cheaper shipping,USPS has had better rates lately,if you go with 5-7 day ground