It’s probably pretty large lol most will sell, eventually. It can take FOREVER for certain things to sell at the asking price, even if it’s similar to the market pricing. I know because I’ve had stuff on eBay for months and just randomly get notifications that an item has sold that I forgot I even had listed 😆
So I do alot of dumpster diving. And I'm always finding random boxes that people illegally dump. It's alot of my best finds actually. Found some old toy train sets the other day you should try that cause I find random old stuff people throw away all the time. And it's free lol
Facebook marketplace , local radio like swap shop. Look all around your area for new signs especially when it's warm. Facebook groups will also post them as well.
I usually sell everything unless just not that great of an item. Most of the few items that don’t sell are junk and stuff I have very little into or got for free. I have a large inventory and I sell fast and slow items daily. It has allowed me to do this full time