I would say that it will be better if you would decide how much you value your free time or how much it cost. You see, investing require a starting capital, which you can lose in case of a failure. Participating in bounties only cost your free time. If you have plenty of it, go ahead, take part in some campaigns, if you dont (but have money), then go with investing, as it will require free time only at early stage when you make decisioun where to invest.