Why would a company not try to sell a product? In the end, it's just an item in the database, so 'disabling' / whatever appears useless to me, and the coin having been sold appears more plausible to me.
Back in 2011, when spot was $32, this 10 kilo coin was not extremely expensive at 11,000. A 'normal' kilocoin costed then also 950; so 10 of them giving 9,500. Later on, when price rose to $40-50 and hung for months on $39, the kilocoins costed even way more, and people paid for them (not me though haha).
So your +50% is likely todays case. It's rather expectable seeing the Mint applying such a premium, in the end, the profit that a company makes is an amount dollars and if the spot price drops, at a same % that amount drops too, which they try to compensate with higher %.
And I have liquidity enough in coins, in fact I started to buy kilocoins because I could swim in the 1oz small silver change haha. The 10 kilo lunar I saw more as a wannahave combined with all other lunar rabbit weight versions, a kinda 'full series', and maybe as extra this delivering an extra value.
Numismatic is not within my interest, I just buy the coin designs I like, without starting to pay geeky premiums. Although seen from today, with my $30 average, what I paid comes down to geeky premiums anyway.