What I want to ask is that how much Bitcoin do you want to earn?
I have my arm and you have yours, you might want some that worth more than what I want so I don't think theirs is a specific enough amount Bitcoin someone might intend to get, although no body will see everyday profit and quit especially now things are rough.
Retirement is only for a government employees or company workers and not for investors and the only reason why government employees agreed for retirement is because the government also pays them pensions monthly or yearly so they aren't losing anything anyway but if you think of retiring from Bitcoin investment then you are lossing.