I bought a $50 macro extension tube set and supposedly it was meant to work with our D3100/D3300. One of the lenses works on mine and two on the other. I could get a full refund if I returned it to them but at $20 freight I couldn't be bothered over such a small amount of money. I approached paypal on their thoughts and they agreed to give me half back.
As mentioned above if it has moving parts I'll pay extra and go local and save ebay for simple things.
I have bought two Chinese camera backpacks off ebay and both are excellent.