I am always investing icos 0.5 eth or 1 eth. Not more and not less than that because that is good amount for me. If i invest more that is painful waiting time for me also you know we can not predict the future market . If ico said us about lock up like 2 months 3 months that means tokens will be released in very good bull market or very bad bear market. So  you can invest more if you dont need to wait like 2 3 months.