Or it is someone who doesn't bother with the hassle of trying to sell things over the internet and ship them, etc for items worth less than $100. They're a SWE who is making $200k/yr, overworked, already have other hobbies and selling something on ebay for $100 just isn't worth the mental effort to them.

So they could very legitimately have half a dozen old electronic items worth around about $1,000 per item when they first start trying to sell things.

That's literally my case - it's not worth the hassle to sell small items as I can just keep them, but wanted to get rid of some bulky server & network equipment as it was taking up significant space (fairly niche & specialized, I can't imagine those having much malicious activity around them).

In this case, what's the proper set of steps to level up your account so you can sell electronics?

I got my account banned instantly despite having a significant history as a guest buyer (with same email & delivery address) as well as an old account with a successful 4-figure sale that I ended up deactivating long ago.

Also, if selling electronics (or any other risky categories) is a no-go and an instant ban, why not just prevent posting such listings to begin with, or require additional verification upfront to deter malicious activity?

Sell locally on Craigslist or Facebook Marketplace. You'll avoid scams from fake buyers that way also, if you limit yourself to in-person cash sales.

Sell one at a time.

this cannot be the solution.

something that is immediately better is allowing users to tell the system that you are setting up an inventory. just imagine people opening an account to do some online e-commerce and trying to set up their inventory...