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In this article I am going to calculate the expectation values for the second grab bag raffle.

Update: use the continued article if you want to buy a bag (or get a free bag you may be entitled to and haven't already claimed). There are still plenty of bags available.

There are 200 bags, each with some prize in it and which each cost three of the green ones everyone likes (but with those below level 25 getting their first one free), the following is the list of prizes copied and pasted from the announcement.
Prizes:
10000 AUD in 1 bag
1000 AUD in 9 bags
10 Q7 Weapons and 20 Q5 food in 15 bags
10 Q7 Weapons in 20 bags
5 Q7 Weapons and 10 Q5 food in 25 bags
50 Q5 food in 60 bags
1 Q7 and 2 Q5 foods in 70 bags

We will also check the accuracy of:
“Though this one won’t be fundraising as we get funded for the New Player Scheme now”

Value of food
My experience with the food marketplace in eAus is that food tends to go for about a platypus per health point (i.e. Q1 tends to be around 40¢, Q2 around 80¢, etc) which would make the Q5 food offered in this raffle cost one of the little gold coins oversea visitors have trouble with.

However Q5 food tends to be offered for higher than $2.00 in the marketplace so I will also calculate for a $3.50 value which is similar to what people are trying to get for Q5 food just in case there is someone who just buys the high end food without bothering with such trivialities as value for money.

Value of weapons
I don't have much of a clue what the value of Q7 weapons is because there aren't any on sale in eAus as far as I can tell but Q7 weapons have 1⅔ the firepower and durability of Q6 weapons so they are nearly thrice as powerful and so should sell for about thrice as much as Q6 weapons.

Current Q6 weapons are going for not much more than one red back so I'll assume $75 (3×25) as the value of a Q7 weapon.

Q6 weapons used to go for about $40 and Q7 weapons may end up going for that price so that will be the low end estimate of weaponry value, a high end estimate can be obtained by tripling the $40 old Q6 weapon price to get $120.

Cash prizes
The $10,000 prize is in one bag and so with 200 bags the expectation value for that prize is $50. The $1000 prize in in nine bags and so has an expectation value of $45.

This gives an expectation value of the cash prizes of $95.

Food prizes
Food is distributed among the bags as follows:
20 Q5 food in 15 bags
10 Q5 food in 25 bags
50 Q5 food in 60 bags
2 Q5 food in 70 bags

The expectation value can be calculated summing the expectation values for each of those as follows:
Σv_foodn_foodn_bag÷200
where v_food is the value of a unit of Q5 food, n_food is the number of units of Q5 food in a bag and n_bag is the number of bags containing that quantity of food.

This gives an expectation value for the ‘realistic’ value of $2.00 of $36.90 and for the high value of $3.50 of $64.575.

Weapon prizes
Weaponry is distributed among the bags as follows:
10 Q7 weapons in 15 bags (along with some food)
10 Q7 weapons in 20 bags (without any food)
5 Q7 weapons in 25 bags
1 Q7 weapon in 70 bags

As with food we will sum the expectation values for those bag configurations as:
Σv_wepn_wepn_bag÷200
where v_wep is the value of a Q7 weapon, n_wep is the number of Q7 weapons in a bag and n_bag is the number of bags containing that quantity of weapons.

This gives an expectation value for the ‘realistic’ value of $75 of $204.375, for the high value of $120 of $327 and for the low value of $40 of $109.

Total Expectation Value
For the ‘realistic’ values we get an expectation value of $336.275 which gives average winnings of $36.275 and a return of $1.1209 for every five kangaroos.

For the high values we get an expectation value of $486.575 which gives average winnings of $186.575 and a return of $1.6219 for every dollar.

For the lowest values we get an expectation value of $240.90 which gives average losses of $59.60 and a return of 80.3¢ per dollar.

Value of each bag
Here we will calculate how much each bag is worth.

10000 AUD in 1 bag
This is pretty obviously worth $10,000.

1000 AUD in 9 bags
These nine bags are pretty obviously worth $1,000

10 Q7 Weapons and 20 Q5 food in 15 bags
The ‘realistic’ value is $790 with a low of $440 and a high of $1270

10 Q7 Weapons in 20 bags
The ‘realistic’ value is $750 with a low of $400 and a high of $1200

5 Q7 Weapons and 10 Q5 food in 25 bags
The ‘realistic’ value is $415 with a low of $240 and a high of $635

50 Q5 food in 60 bags
The ‘realistic’ value is $100 along with a high of $175

1 Q7 and 2 Q5 foods in 70 bags
The ‘realistic’ value is $79 with a low of $44 and a high of $127

Probability of ‘winning’
Whilst all bags have something in them, not all bags are worth more than $300 which is defined here as the minimum value for a bag to be a winning one as that is the cost to buy a bag (except for the free bag given to those below level 25).

With these constraints under the ‘realistic’ and high end value estimates getting anything but the 60 bags containing 50 Q5 food and the 70 bags containing one Q7 weapon and 2 Q5 food would count as winning. That leaves 70 winning bags giving a probability of winning of 0.35 per bag bought.

Under the low end value estimate the 25 bags containing 5 Q7 weapons and 10 Q5 food is also a losing bag reducing the number of winning bags to 45 and reducing the probability of winning to 0.225 per bag bought.

A Warning
This is gambling, whilst the chances in this raffle are relatively good compared to ozLotto or a casino you most likely will not win more than you spend so don't bet what you can't afford to lose.

That said I'm going to buy two bags as well as my freebie.