Taking a break from all the New Announcment threads and was reading over the Prestige Enhancements and thought I would throw out a short 'Cost' list as I found it pretty interesting.

I tried to use the cheapest way to get each one and the cost is calculated for Tier 3 on all of them.

Assassin: 38 AP's, No Feats

Hunter of the Dead: 35 AP's, No Feats
Defender of Sybrys: 32 AP's, 1 Feat
Knight of the Chalice: 24 AP's, No Feats

Kensai: 34 AP's, 5 Feats (Note: All feats but one have Figher level requirements)
Stalwart Defender: 26 AP's, 1 Feat

Frenzied Beserker: 30 AP's, 1 Feat

Tempest: 14 AP's, 7 Feats (Note: 3 of these you gain as Class Features)

This may have been posted elsewhere and apologize for the redundancy if it has.