What time and effort, buying a fuse and replacing it? Locating cars and other items on these apps doesn't take much skill, or time...so to be real, that's a great way to make $3k. Oh, wait.. a "measily $3k" .. something I always touch on, jealousy and hate at its finest. The same ones referring to it as chump change, and not worth it, are the same ones that are usually broke and don't have money to even invest in a domain and hosting, let alone setup a good marketing campaign.
OP, congrats on the great find on offer up. I actually listed a few items on there and 2 other tag sale apps for a friend over the past 2 weeks, because she didn't know much about it or have the time to do it herself. Surprisingly, thone apps get a decent amount of traffic.. I sold one items (brand new Toilet in the box) in a day, and the pool table sold in 4 days. And I could of sold the pool table quicker if she was strapped for cash, because you get alot of low ball offers on there, but she held firm on her price. I have one last item listed, which is a Spalding glass backboard basketball hoop. Been getting alot of hits on it, but again she's firm on her price so I've turned down alot of people. She's giving me a 30% commission on these items, so it's not bad.. I initially was doing it for free, but she insisted.
But to anybody looking to make quick cash, I would definitely take the OPs advice, these tags sale sites do sell your stuff pretty fast. A twist to the method is, finding items that are in popular demand on wish/aliexpress/etc and then selling them for a profit on the app. You would be surprised how well the right items do on there.