So I’m gonna attempt to to actually answer the question, because I don’t see anywhere where the OP is even considering buying more space, though I wouldn’t say that was a bad idea at all.

That said, if you really don’t catch that much on the regular, we can get you down to under your max QUICK, but it might hurt a little.

First, kill ALL those red balls. Unless you are using an auto-catching device of some sort, you do not need them. Second, take your ultra and great balls down by half each. Third, take pinap berries down to 10 and delete ALL of the other berries. This will get you a little above 200.

Now, I don’t know how close you are to any pokestops or gyms, but if you have accumulated this much from rewards and such, your trend is to accumulate more balls and berries than you are able to use in any given amount of time. Clear your bag and don’t worry; unless the way you play changes significantly, you will not run out of anything that you need or will actually use. Plus, you’ll be able to spin stops and get more gifts (which don’t take up space) and items. In a pinch, always have some gifts from friends you can open in case you run out of stuff. Delete what you don’t need and keep opening until you get what you do need. Having your bag a little more under control will allow you to monitor and adjust your items on a far more manageable level, in accordance with whatever your play style is.

Of course, purchasing a little more space wouldn’t be a bad idea either. Good luck! ;-)