How do you know ? Proof ? ..... Wait, you accepted that Darkcoin has instamine ?
Unlike you, I was there since late January and saw what was happening in WTS/WTB and the rate upon hitting ccex, and the consequent transactions and volume.
Even if someone WASN'T there, they can find the messages in the thread "hey WTS 10k DRKs for 0.25btc"
CCEX chart upon entry was 0.00001 (10k DRKs for 0.1 btc), quickly adjusted to 0.000025 to reflect prior volume that was taking place through pms.
The proof you seek is in the thread pages (WTS/WTB)
https://bitcointalk.org/index.php?topic=421615.msg4889177#msg4889177https://bitcointalk.org/index.php?topic=421615.msg4861558#msg4861558 + the charts of ccex and poloniex.
As for the instamine, Darkcoin is not instamined because that would imply the whole monetary base is instamined. This is true for pow/pos hybrids.
A number of ~2m coins though WERE instamined over the first 2 days. Did they appreciate these coins? No. They sold them for pennies because just because one makes a coin doesn't mean it has value. At that period there were 10 coins coming out per day, all shitcoins - so why would anyone pay much for these? Dark gave value to worthless coins by innovation and anonymity (introduced over a month later).