Thanks Az for the question.
I do agree with you - we are not consuming enough - and certainly not compared to what we are producing.

It's not an easy question: "what is too much"
But I'll try to outline my underlying guiding principal here:
I tend to think a healthy economic cycle usually aligns with the typical risk/reward dynamics that open markets usually see:

• Low Risk - Lower expectation for return
• Higher Risk - Higher expectation for return

Further, in an economic production cycle, each production step should have an expectation of value added, and each step adds cost and risk.

So translating that to SPL, where the final output of Land is to make products to sell profitably to other players...
At this point we already know what most players will pay for cards and assets. So unless the ecosystem expands rapidly, we can probably make a pretty decent estimate of the value of many final outputs, with a bit of a premium or discount based on individual asset characteristics.

But then whatever the output price, the land economy will split the total value added through the production cycle.

Grain production is the classic "low risk" business model in SPL

• It always produces more than it sells
• Selling price scales 1-1 with input price since it just produces more than what it consumes
• Further, we have barriers to entry which limit competition

Then, the final steps - producing SPS, Aura and Research, have the most risk - they risk all the price and supply shocks from all previous steps and they have the most market risk, since they aren't immediately sellable outputs in an LP.

Since Grain is the fundamental first step of land, we need grain to be plentiful and available... yes, it should have an ROI. But if we want to encourage the later steps, we don't just want a "stone anomoly" - we want all the subsequent production steps to have their own anomoly relative to grain: a "wood anomoly" and "iron anomoly" too. And at the end, the "Aura anomoly" should have the highest expected result to compensate for the highest risk - that's the sign of a healthy, non-stagnating, market, which will justify why Aura gets locked behind a research permit....

Pulling demand from end cycle production should have much better results than trying to push early cycle production value - which just means passing higher costs to everything afterwards without adding to those value chains (aka inflation).

*Success will come when late stage production outputs can "pull all resource prices". The goal should be an EXCESS of utility - whether functional, economic, or cosmetic.... by having so many things to buy with AURA that we never hear "I don't have anything to spend my Aura on"...

So to rephrase... What is "too much"?
To me, if grain ROI is higher than equivalent wood/stone/iron ROI, then it's too much: grain price is too high of a share of production value, and you fix it by adding production at the end of the production cycle.

(Sorry for the long response - maybe it should have been a blog post of it's own :D)