If you don't want to sell stuff, I can't help you. If it's just the process of selling that you hate,...
You probably sell every day. Taking a compelling photo isn't about making a grid of a few million dots, in different shades and hues. A compelling photo is about the viewer. Who's going to see it and what do you want them to feel?
So too with selling. It's not about the particulars of what you want to move. An effective sale is about what you want the buyer to feel. And for the purposes of overcoming SAS to support GAS, effective just means motivating yourself to go through the steps. If you've got an extra lens, remember how excited you were to get it, feel that excitement again and imagine the next guy feeling the same. Then you're not selling, you're sharing.
And don't think of selling as punishment for a bad purchase. Sometimes your needs just grow or shrink or change. Think of ownership as a rental and selling as getting your deposit back.