hey, i'm a 43 smn that needs his puppy too,
but honestly you're gonna be looking at paying about a million gil a person, depending of in you need to fight the prime avatars to get thier whispers, cuz he's worth that kinda gil later on.
as much as i want my purple puppy, i'm not looking to shell out in excess of 5 million gil to get em. i'm gonna raise my level and fame, fight the primes, and then get em.
level up to 50, get some LS mates to help you fight the primes, and then try to find some help for your fenrir fight. 5 70+ smns can take him quite easily, especially if they already have fenrir.
besides, if you have all the avatars *sans fenrir*, you're just as equipped as you need to be.
good luck though, and if you find anyone that'll do it for cheap lemme know lol