Determining my profit?

[Jordan Solomon]

Hi. One thing I'm still confused about how to come up with my own profit amount. I always hear, of course, that you take 70% of the ARV and then subtract repair costs and then your profit amount, but how do I come up with that profit amount? Is it just "what I want to make," or is there any kind of objective rule of thumb to determine how much is "fair" to target? Thank you.