For bags that I have a difficult time selling, I just give them away or sell at a very low price (like under $100). I’ve given away tons of contemporary bags I’ve bought over the years and never felt bad about it. No use keeping something I haven’t used in years. Sure, I might’ve spent $$$ on them, but I used them and loved them to death.
The only time I feel guilty is if I end up selling something I only kept short term (ie, a year or under) because I feel like I wasted my time and money. I’ve done this with a lot of premier bags, some of which have had great resale value.
For clothes, I donate. No consignment or eBay, just straight donation. I don’t own any RTW or very high end labels, so to me, I don’t see the point of trying to sell those, even if they are department store or boutique brands. More power to those who sell clothes online; for me, I’d rather not deal with the hassle.