NEO's current price is ~ $108, so I believe the parent post is saying that NEO represents somewhere around 1.6% of the market cap of top 25. Since you must buy at least 1.0 NEO, if you want to balance things out just right, you'd need to have a total investment of at least $6700.
Anything less and you either have to leave NEO out entirely or you have to still have the minimum of 1, which will be a larger share of your holdings than its relative market cap.
Anything less and you either have to leave NEO out entirely or you have to still have the minimum of 1, which will be a larger share of your holdings than its relative market cap.