Personally, I am not a fan of buying used unless you know the seller and know the products are in good condition. That said, an ivy i5 would probably trade blows with the hyperthreaded pentium, faster and smoother in games that use lots of cores, and a bit slower in highly single threaded games. If you are buying a gpu, the 4 gb RX470 is the best value for the money, especially if you can find one on a good sale. I think they can be had for 150 bucks or so. The 1050 Ti is a great card for someone who has a psu without a six pin connector, but overpriced otherwise for the performance in gives. Might be nice in a mini system like you are looking at though--very low power and decent 1080 performance, although much lower that the 470.