If the spot price on gold stays about where it is now (between $1,100 and $1,149), the opening price for the Mark Twain gold coins should be about $381 for the proof and $376 for the uncirculated (per the Mint's pricing schedule). (Note: Prices do not include the initial discount typically offered by the Mint for orders within the first 30 days of release.)
Per the coin's authorizing legislation, the selling price of the coin is to be equal to its:
1) Face Value +
2) Specified Surcharge +
3) Cost of Materials (e.g., precious metal content) +
4) Cost for design, production (labor and machinery), marketing, distribution and overhead expenses
Let's breakdown the price on the uncirculated coin starting with its sale price:
Selling Price: $376
- Face Value: $5.00
- Surcharge: $35
- Intrinsic Value of Gold: ~$272 (assumes a spot price of $1,125 per troy ounce)
These total ~$312.
That leaves ~$64 for all design/production/distribution efforts.
I don't think $64 per coin is too bad considering all the Mint needs to do to produce and administer a commemorative gold coin such as the 2016 Mark Twain piece. At the current spot price of gold, the Mint's design/production/distribution costs represent about 17% of the coin's selling price. This percentage would go up or down based on changes to the spot price of gold.