This is a very tricky question to answer. We all live in different areas of the country and have different “standards of living”, so the “cost of living” will be different for us all.
That is going to be a personal preference thing based on your own personal goals/objectives; however, I like to look at it like this as I think it is a good way to put things into perspective.
To make $100 using $100, you need a 100% gain. To make $100 using $1,000, you need a 10% gain. To make $100 using $10,000, you need a 1% gain.