$150 is fine as an initial deposit and as an amount that has to be kept in the poker balance (as opposed to the payment processor - poker sites are sometimes less secure as Black Friday has taught us) to enable playing a long 4-6-tabling session smoothly (for masstabling, the rule of thumb is to keep 2 BI per table in the account).
However, as said above, you'll most likely have to redeposit at least once. I don't like thinking in terms of a bankroll separate from the liferoll... because I treat one's entire net worth as the united bankroll (for all investments, not only poker), but with this approach, the winrate and chances of losing have to be evaluated very conservatively, so make sure you have 6-month life expenses (assuming that 6 months will be enough to find a job if poker goes wrong) and a 'test bankroll' (enough to play 50-100K hands no matter what, to get an estimate of the winrate... that's 30-50 BI).
I'm grateful to my fate for not letting me spew money away with this approach (I was going to buy an apartment fast, not realising how poor this investment is, and thus treated only a tiny part of the bankroll as the liferoll), but note that most people don't have as severe issues as me. Anyone adequate and smart should be able to spin up easily from 40 BI for PLO10 imho.