You don't need the money
When looking at piles of clutter, maybe your inner Reluctant Discarder is whispering: You spent $125 on that dress last year. You should try to sell it.
The first rule of mental health is to stop “shoulding” all over yourself.
The truth is, you don't need the money. If it were easy to sell your items for a good price that was worth your time, you'd have done it already.
If you needed the money, like really truly needed it to buy food or pay rent, you either wouldn't have bought the stuff in the first place, or you would have sold it long ago. If the stuff just disappeared overnight and you couldn't sell it, how would your life be worse? Would your electricity get cut off? Would your kids miss meals? No? Then you don't need the money.
If you want a peaceful, calm, decluttered space, you'll donate the items to one place at one time. Boom. Done. If you want a project, a time suck, and drama, you'll try to sell things.
Some people sell things easily and quickly - and they typically aren’t reading decluttering blogs. If you were able or willing to sell things quickly and easily, you wouldn't be reading this. You would have done it already.
To get to the top of the mountain, do yourself a favor and donate your unwanted items.