I don't understand your logic, there will be around 6 times more drk than there are now in circulation, so more offer means low price (obviously not if more buyers, i know, but this is applied to nxt too without increassing the supply)
The tech is much much much better in nxt than in drk, drk is a bitcoin clone with little tweaks for anonimity, nxt is a platfform which can do the same as bitcoin plus many more things that none bitcoin or any clone will can do. It will include anonimity too, so what will darkcoin offer that nxt don't?
If nxt reach same market cap as BTC they will be at 5,4$, and in my opinion, nxt have much more chances for achieve this than darkcoin.