Advice on purchasing a gaming PC

[cwhlr]

Hello everyone. I am currently searching for a gaming pc for moderate gaming. I have searched brand names like the dell inspiron and HP gaming desktops, used custom built pcs, and have also toyed with the idea of building my own. I'm weighing the pros and cons but would like some input. I am wanting to spend around 500, but will go up to 800 potentially. I have found a computer on criagslist with the following specs listed for 589.
CPU: Core i7 3770 @ 3.40GHz w/ 3.90GHz turbo boost 4core/8thread
MOTHERBOARD: ASUS Z77-A, LGA 1155 ATX motherboard
VIDEO CARD: EVGA GTX 1060 3GB
RAM: 8GB ddr3 1600 MHz (2 x 4GB sticks in dual channel mode)
HDD: Seagate 1TB 3.5" 7200 rpm mechanical hard drive
OS: Windows 10

What are yalls thoughts on this system, and do you have any tips on what I should look for or test before purchasing this system. Thank you for any advice or input in advance.

 

[Lucky_SLS]

For 800 bucks, you can build a great 1080p 60fps rig like this :

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 2600X 3.6GHz 6-Core Processor ($188.99 @ Amazon)
Motherboard: Gigabyte - GA-AX370-Gaming ATX AM4 Motherboard ($79.89 @ OutletPC)
Memory: G.Skill - Ripjaws V Series 8GB (2 x 4GB) DDR4-2800 Memory ($79.99 @ Newegg)
Storage: Crucial - MX500 250GB 2.5" Solid State Drive ($59.99 @ Amazon)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($43.35 @ OutletPC)
Video Card: Asus - Radeon RX 580 8GB DUAL Video Card ($249.99 @ Newegg)
Case: Corsair - Carbide Series 275R (White) ATX Mid Tower Case ($44.99 @ Newegg)
Power Supply: EVGA - SuperNOVA G3 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($49.99 @ B&H)
Total: $797.18
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-07-23 04:32 EDT-0400

 

[Ztdutxjgxgtu]

First choose your target ,
Game at 1080p 60fps? 1440p?
Gpu gives the most output.
Eg gtx1060 for 1080p , gtx1070 for 1440p
Then choose a ryzen 2600 or above with fast ram
You can then adjust other parts to fit your budget

 

[zoltan.boese]

Drawback of a 3rd generation Intel system is, that you can hardly find a motherboard or cpu, if one of those has to be replaced. Used parts are scares and expensive relative to their performance. Therefore it is not a future proof choice.