1 drink ration = 1 embark point
1 dwarf consumes on average: 2 meals and 5 drink rations per season
4 seasons per year x 12 years (dwarven childhood) = 48 seasons
48 seasons x 2 meals = 96 prepared meals (prepared meals don't spoil, so they can be stockpiled for the entire childhood of a dwarf.)
48 seasons x 4 drinks = 192 drink rations
96 x 7 (672 prepared meals)
192 x 7 (1,344 drink rations)
so, 1 unskilled peasant = 288 embark points
x7 = 2,016 embark points (2,016 prepared meals or drink rations)
1 adult yak = 101 embark points (101 prepared meals or drink rations)
embark travel time is 2 weeks, which is 1/6th of a season. During that time, the seven new dwarves will consume 2.3 (3) meals and 4.6 (5) drinks. The yaks are assumed to eat along the way, so thier feed isn't counted.
(101 x 2) + (288 x 7) + 3 food rations + 5 drink rations = 2,218 meals or drinks, 3 meals and 5 drinks
So, a new embark costs the Mountainhome a base of
3 logs of wood + 2,218 prepared meals and/or drink rations + 3 meals (raw is OK, since it'll be eaten before it has a chance to spoil) + 5 drinks
Dwarves with experience in certain skills will cost 1 food/drink ration per 10 experience points of each skill:
Novice +50 Food/Drink rations
Adequate +110 Food/Drink Rations
Competent +180 Food/Drink Rations
Skilled +260 Food/Drink Rations
Proficient +350 Food/Drink Rations
These costs are a per skill, per dwarf expense on top of the base required for a team of seven peasants. A proficient carpenter who is also a proficient brewer would cost 350 for the carpentry skill plus 350 more for the brewer skill, an extra 700 rations for that dwarf alone.
So that's what I'm going to require be given to the caravan at the Depot to even purchase a new embark team. However, this is where the useless crafts and other sellable items can come into play: Whatever can be purchased off of any of the other civs is able to be spent towards the embark totals or even stored at the Mountainhome to be available for future embark teams.