Buying "off-market" is all kinds of trouble if you're paying higher than tracked market data but to your advantage if you're buying under tracked market data.
It’s been impossible to find one for 18k for years. Like it or not, prices have gone up on them even while I was trying to buy for years until I gave up to pay even 25k. If you want a ring that doesn’t do a whole lot, you’ll be looking at the 12-18k range, but this ring doesn’t fall in that category.
Given how much they are used and the rarity as an older ring, 33k isn’t impossible either. Higher than I’d expect given prices in the last year, but there’s also a point where price increases are going to be more exponential to a point given that there are only fewer and fewer Xmas 2016 rings in-game.
His prices are not manipulated; I can confirm the last Christmas Ring 2016 (that I know of selling) sold for exactly 33,000 PED on July 20, 2021.
Care to know how I know? I was the purchaser.
The post of the sale thread is still on the forum and whether or not I purchased it over the perceived "value" the market value at time of trade is determined individually by each buyer & seller.
If someone offered to sell one for 18k, I'd immediately pick it up for my wife.