My views are around 15% per annum but it would take around 6.6 years to earn the initial amount back. Would it be a bad decision?
This is actually a good plan for your return. It's not asking that much and it is achievable but you should be also open to some unusual results at the end of the day or the month.
In business, there's really a wavy journey and you can't be sure with the given timeframe that it will be followed smoothly. The path that you're going to take isn't just a straight one but with a lot of curves and frustrations.
What you need to add is about the possibilities of what if that plan is being prolonged by a situation and you should be okay with that.