Introduction
The answers will be based mostly on the needs and wants you have described in your question, but also on my experience with DnD.
Lingo
I'll be using a improvised shorthand for some expressions and term in order to speed things up. List follows:
- CURRENCY(-IES): a type of coin, either copper, silver or gold
- GOLD: Gold coin(s)
- SILVER: Silver Coin(s)
- COPPER: Copper coin(s)
- ONE: A coin of any CURRENCY, value of 1. [Same is applied for all numerical denominations].
- VALUE: Numerical denonimation (e.g. 1, 2, 5 and so on)
- 12SET: The set of twelve coins
- 10SET: The set of ten coins
- COST: Money spent on certain combination
- COUNT: The total number of coins received for a given combination
- MAXLOOT: The maximum loot per adventure as stated by the questioner
- WORTH: The total value of all combined coins.
Base
Since you mention that you would like a few ONEs of all CURRENCIES, we'll start of with the different options for this.
Option 1 (BASE1):
1x 12SET COPPER (ONE, TWO, FIVE)
1x 12SET SILVER (ONE, TWO, FIVE)
1x 12SET GOLD (ONE, TWO, FIVE)
COST: $36
COUNT: 36
Pros: You receive a few ONEs of each CURRENCY, like requested, while also getting some other quite useful coins.
Cons: High cost-to-coin ratio. Perhaps too few ONEs.
Option 2 (BASE2):
1x 10SET COPPER ONE
1x 10SET SILVER ONE
1x 10SET GOLD ONE
COST: $24
COUNT: 30
Pros: Lowest possible cost-to-coin ratio. You receive quite a few ONEs of each CURRENCY.
Cons: No additional coins, perhaps too many ONEs.
Suggestion
Calculating MAXLOOT, we get a total value of 296 GOLD and this suggestion will take this into some consideration.
As pointed out in another answer, 10 COPPER = 1 SILVER and 10 SILVER = 1 GOLD. Given this, and the aforementioned usability concern, this suggestion rules out any VALUE of TEN or above for COPPER and SILVER.
While both BASE1 and BASE2 are viable here, BASE2 will be used for its lower cost-to-coin ratio.
Coins:
- 10x ONE COPPER
- 10x ONE SILVER
- 10x ONE GOLD
Metadata:
- COUNT: 30
- WORTH: 11.1 GOLD
- COST: $24
We add:
- 1x 10SET COPPER (FIVE)
- 1x 10SET SILVER (FIVE)
- 1x 10SET GOLD (FIVE)
- 1x 12SET GOLD (TEN, FIFTY, HUNDRED)
Combined, this gives us the following:
Coins:
- 10x ONE COPPER
- 10x FIVE COPPER
- 10x ONE SILVER
- 10x FIVE SILVER
- 10x ONE GOLD
- 10x FIVE GOLD
- 4x TEN GOLD
- 4x FIFTY GOLD
- 4x HUNDRED GOLD
Metadata:
- COUNT: 72
- WORTH: 706.6 GOLD
- COST: $60
This suggestions gives you a wide spread of coins, while maintaining usability. TWOs of all CURRENCIES are not included as I feel that you could just as well use 2 ONEs, and TWOs would just bloat your coin pool unnecessarily.
The higher GOLD (FIFTY, HUNDRED) could be eliminated in exchange for smaller GOLD values, but I think the feeling of holding (or offering, stealing, finding) a HUNDRED GOLD would be highly appreciated by a lot of players.
Finally, using BASE1 instead of BASE2 would also work splendidly. It would increase the WORTH of the pool, but decrease the amount of ONEs. It would, however, exceed the budget of $60.
Final notes
During my calculations, I started working a spreadsheet for calculating the various outputs. In it current stage, it's very user-unfriendly, but I'd be happy to share it (after I've revamped it a bit, that is). Let me know.
Hey I Can Chan - of course there's plastic alternatives, but these things are beautiful. To each their own investment, or in my case Christmas wish list.
– JoeAnglican Oct 21 '14 at 23:57Please, JoeAnglican, rephrase/restructure the question, so that we can answer it objectively using the brilliant power of Math. :D
– Gunnar Södergren Oct 22 '14 at 14:04