Hey, I ship with tracking and insurance too, and your costs are pretty close to mine. It's probably cost me a few sales, but I'd rather lose a sale than lose an item in the mail, or get screwed over by a customer falsely claiming something wasn't delivered.
I think the difference is that my jewellery is much more expensive than yours, and when you pay $900 for a ring, another $30 for shipping isn't such a big deal, but when the shipping price is almost the same as the item price, people might find it more off putting.
People on Reddit feel like they need to make their opinion known on everything, and never feel the need to sugarcoat it because the anonymity of the internet lets them get away with being dicks. You do need a thick skin to deal with reactions, sometimes.
And the best way to deal with the downvoters is simply 'don't feed the trolls.' Downvote their comments, and move on.