Are you thinking about buying it now or do you want to wait and see if the price drops more before you build your setup?
The thing is, GPU prices in Brazil are pretty unpredictable. It could go down a bit more, but it could also stay at this level or even go up if there's a stock shortage. What's different is that the 4070 Super has probably been on the market for a few months now, so you won't see the kind of price swings that happen right after launch. If you're already wanting to build your PC now, I don't recommend waiting around for months hoping for a drop that might never come - the performance gains you'd get from gaming over the next few months are worth more than saving a few reais.
The other thing to consider is whether there's really nothing newer that's worth it. Graphics cards are always evolving, but if the 4070 Super is hitting your goal of 1440p with high quality and handles 3D modeling well (which seems to be the case), get it now and enjoy it. Just don't buy in a panic - compare prices on like 3 or 4 sites before you buy, because the difference between stores here is huge.