Ok, let’s stick to this notion of expected value because it plays both for the land owner and for the transit system builder.
To get back to your post, the plan was to buy an area, build a transit system in the middle of it, then sell the rest at a higher price. If you fail to buy all the land you need (or at least enough of it), you may give up on the project, in which case the value of the land does not increase. So indeed, as the transit system builder, the viability of your project (and the profit attached to it) is linked to the probability that you indeed acquire the land you need (both the land to physically build the transit system and the land around to sell later at a higher price), as well as the price at which you will be able to buy the land first, and re-sell it after completion.
Now, if the land owner are correctly calibrated, and they correctly anticipate the odds of your project being a success, your expected profit on the sale of the land must be zero.
If, on the flip side, you expect to make a profit because the land owners will underestimate your ability to succeed, will not see you coming, not understand what you are trying to do, or something along those lines, then your strategy relies on the market not being efficient. If this is the case, I think this is a crux.
You get back to the point of projects being mutually exclusive. Can you elaborate in your example on why the projects would be exclusive?