People should not just buy small amounts of Bitcoin to try to acquire more bitcoins in the future.... you should make the Bitcoin price work for you. I also started out by buying bitcoins on a weekly basis.. but I felt that was the wrong strategy. (You say you can only buy every other month.... and that is forcing you to buy at any price.... )
The best thing to do is to hoard your money and then to wait for the Bitcoin price to go low.... then use all that money to buy at a low price and then when the price goes up... you sell those coins for a small profit and hoard the profit... until the price drop again.... then you buy again. (Just watch the fees ... and only do this if you made a good profit... that are way more than your fees)

It's really hard to predict Bitcoin's market since everyday there's people buying and selling plus at the same time the events such as economically, politically or international. DCA actually gives you the peace of mind by just having a fixed amount and schedule to buy BTC without a hassle of checking and analyzing the market. Timing when to enter the market is actually good if that's your technique and suitability cause some people doesn't have the time to check the market all time so they would just simply invest at the end of the time. I think this would only applicable to people who does have a lot of time, cause work plus crypto might be draining but investment is a must. Cause I actually do both when I have free time and spare money I would choose this but most of the time its DCAing.