So what you are worried about is an upward trend reversal?
Why would you buy everything in 3.05 then you sell half of it for the same price? It is a waste of trading fees. I suggest you better buy 50% of the total budget and the remaining 50% you can set a stop limit (buy) at the trigger price of 3.075 and the limit order at 3.08.

If the price continues go down, you can cancel your buy order.