You've agreed that:
1. The value of money is its purchasing power in goods and services.
2. Scarcity of goods and services drives prices up, which reduces the value of each bit of money.
3. Amount of labor invested is not always correlated with the amount, quality, or price of goods.
These points all lead to the conclusion that:
1. Goods and services are inherently valuable.
2. Labor is valuable to the extent that it can be converted into goods and services.
3. Money is valuable to the extent that it can be converted into goods and services.
This isn't what you're concluding, however. You're concluding that the value of money is its ability to command labor, not its ability to command goods and services. This is despite conceding that prices -- which you have defined as the same as the value of money -- are directly correlated to the scarcity of goods and services, and not to the expenditure of labor.
Your argument to defend this is:
1. If no labor, or at least "work" in a scientific sense, is done, no matter how small or incidental, then money has no value.
My response is that if no work in a scientific sense is done, then no physical forces exist. But physics, while necessary for money to exist, is not sufficient. Similarly, if no humans burn calories, then we're probably not dealing with money, since humans invented money to regulate human interactions. But humans burning calories, while necessary for money to exist, is also not sufficient for money to have value.
A little reflection will show that labor is expended as a result of the potential value of the goods and services that can be acquired by doing so. If you take goods and services away, labor alone has negative value: it is exertion without a product, and people will actually pay to avoid it. Labor, like money, is not inherently valuable, but derives its value from your ability to convert it into goods and services -- and just like money, if you can't get much stuff with your labor, it's not very valuable.