Does this 10,000 zł PC build look well balanced?

The first thing I’d check is the motherboard. If you want more current features and connectivity, compare the price of a B850 board rather than choosing B840 by name alone. Also, a 1200 W supply looks larger than this build is likely to need. A good-quality 750 to 850 W unit should be a more sensible place to look, unless you have a specific future upgrade in mind.

The 5.55 g tube of thermal paste is plenty, and the cooler may include paste already. The 1 TB SSD is the part I’d most consider expanding if you expect to install several large games.

For a gaming-focused build at this budget, I’d compare the cost of the 9600X with a faster gaming CPU, including the 7800X3D if it’s priced reasonably where you’re shopping. The RTX 5070 Ti is a strong graphics card, so spending a bit more on the processor could make sense depending on your games and resolution.

I wouldn’t cut the memory just to chase a lower price. DDR5-6000 CL30 is a reasonable match. Check actual Polish retailer prices before deciding, since the best-value option can change a lot by store.

Don’t pick a processor just because people say one brand has no issues or is automatically better value. Compare independent gaming and productivity tests for the exact CPUs you can buy, then check motherboard cost and power use too. Different recommendations here point in different directions, and the right choice depends on what you’ll do with the PC.

Whatever you choose, verify the board supports the CPU out of the box or has a practical BIOS update method. That’s a more useful compatibility check than relying on the chipset label alone.

Looks broadly workable, but I’d price the whole list locally before locking it in. The PSU is the easiest place to avoid overspending: choose a reputable model with enough capacity for the GPU and a little headroom, rather than paying for 1200 W by default. I’d also check whether the case includes the fans you want, since that can affect the final cost.