EVE New Citizens Q&A

Except the "value of the minerals" is an arbitrary value assigned by you. If a couple million isk for each hour of your time seems like a fair trade to you, that is by definition the value of the minerals/products in your case, regardless of what the mean market value of them is.

Since Eve has infinite resources demand is also the primary setter of price, and that kind of market results in oscillating prices for goods and currency value, so sometimes a finished module is going to be "worth" less at one time than the minerals comprising it at the same (or a different) time, the two variables are linked but there's some control delay factor. Longer-term investments where you specialize in making something and produce it at a stable rate will tend to give you smaller but more consistent returns and keep you from losing your shirt in speculation. Undercutting other producers by pricing based on something you don't value much (your time-- let's be honest, you're playing an MMO and shooting rocks, your time means nothing to you) will also chase other producers out of your market by leaving them with an unsellable stack of "properly valued" turrets or whatever, so "minerals I mine are free" is a great philosophy for carving out that beginner niche.

This is also extremely basic economics.

To be fair, you can do that with a big enough chunk of capital whether or not the items in question are "undervalued" in mineral terms or not. When I see a limited number of something in my region, I'll frequently buy the lot, add 10%, and sell it again, and I'm in no way a dedicated trader.

(A couple of times I've immediately had someone else buy my +10% stuff and repeat the process, so I'm not alone in being this much of a bastard.)