Why cost should not be the X factor while investing?

I see many investors getting into it just because the deal was cheap. Hey, I invested 10 lakhs into this new startup in an “emerging market” and since it came at a throw away price I invested in it.
Thats a wrong investment decision. Lets understand why?
The real estate prices in a remote area with no accessibility to internet, poor transportation and no connectivity full of low income people who barely make a living will be 10x cheaper than those in Metros and cities. So, setting up showrooms and malls will be cheaper but will that be viable? Obviously not. Because due to the low income of the residents there their paying capacity will be too low destroying consumerism. Showrooms and malls if set up there will find no returns making the investment completely unviable and a huge loss.
Therefore, cost should never be the X factor in investments. Obviously, cost plays an important role but the mistake many newbie investors make is that they base their decisions only on the cost of investment. A sound plan, a solid vision and clarity of goals coupled with cost effectiveness is an ideal investment option.
Or else you should have the patience of 20-30 years to get the returns out of such low cost investments. Many people especially in India made fortunes by buying lands in remote villages or rather hamlets, foothills acres of land for a mere few hundreds per acre which after a few decades earned them over 100x returns. However, theres a flipside to it as well. Many Indians who blindly followed suit of investing in such remote locations lost their money as well. Those who earned returns are the ones who had some idea about how the place will transform in the next decades, what are the government plans around those areas, factors that would contribute to its development etc. The investors who did some research and studied the plan before buying such lands earned handsome returns. Again, in this case, cost wasn’t the only factor.