All of the comments on here has merit
Buying used is perfectly fine if you do your due diligence. Buyer beware is a good mantra. Audiophiles are for the most part good, hard working intelligent people. We all have income levels we have and what we can afford, and want for our systems. Ebay has less quality equipment, and is so cost prohibitive. I just dont use it, If I dont have to. If it doesn't have the original packing, I am skeptical, there are exceptions. Giving a honest trail of ownership is a way of promoting trust. Just be honest about your shape and cost of what you are selling. I have a rule of thumb of %50 of new. So, most of my equipment, I have is used and I have had some experience with this topic.Good pictures with good customer service, and realistic expectations, and you will be successful and maybe gain a new audiophile friend to promote this hobby.