There are two alternatives to startup path:
Which is the better alternative?
#2 - to me there's no doubt. (and one caveat at the bottom)
Couple of reasons:
If you have a #1-type idea right now - you should drop everything and start working on it right now. I can only assume that the fact you're asking the question means you don't have one yet.
Check out this formula for thoughts on how to value idea versus execution. I'm not saying it's 100% accurate, but you can use the concept to help make your decision.
However, execution may not depend on how familiar you are with the field. Within a short time of starting, you will probably be an expert regardless.
AWFUL IDEA = -1
WEAK IDEA = 1
SO-SO IDEA = 5
GOOD IDEA = 10
GREAT IDEA = 15
BRILLIANT IDEA = 20
NO EXECUTION = $1
WEAK EXECUTION = $1000
SO-SO EXECUTION = $10,000
GOOD EXECUTION = $100,000
GREAT EXECUTION = $1,000,000
BRILLIANT EXECUTION = $10,000,000
To make a business, you need to
multiply the two.
The most brilliant idea, with no
execution, is worth $20. The most
brilliant idea takes great execution
to be worth $20,000,000.
Those aren't the general choices, so I assume you're being specific to your current situation.
Three questions are common to most startups:
Your second case suggests you have good answers to all three questions. Your first may be illusory - lack of domain knowledge makes all of (1), (2) and (3) suspect.
So my thinking would be, you have every reason to progress your 'medium' startup. And your 'gigantic' possibility may need further investigation, and perhaps the involvement of partners who bring the domain expertise you lack.
The unique ideas always work. If you have a great unusual idea, you should probably start with it. If you aren't so familiar with it, you can always find people who are. An average idea seems to be not so risky, but it will not bring you as much profits as a unique one.