whats the average fee now a days for a btc mixer? and how does that compare to using nxt as a mixer? what are the savings if someone wanted to mix 100BTC?
According to the changelog link I posted above, shuffling requires a deposit of 1000NXT. This is about $6.5 right now.
The total fee for each participant in a shuffling is only 12 NXT, this is around $0.08. The 1000 NXT deposit is fully refundable at the end of the shuffling. It is there to prevent intentional sabotage of shufflings by rogue participants - when someone intentionally submits invalid data or does not complete his part, the deposit of this participant is retained. Deposits of innocent participants are refunded in such case.
The main advantage over using a centralized mixer is that there are no trusted parties, coins shuffling in Nxt is fully decentralized. No trusted special nodes, no websites that may keep logs, and of course no need to trust the other shuffling participants either.