Feel free to get a z490. Cheaper. The only thing you lose is PCIe 4 nvme support. For gaming, not even an issue. And the 10th gen chips don't even support it anyway. PCIe 3 nvmes will give you indistinguishable experience for gaming.
I paid $149 for my ASUS TUF Gaming Plus z490 (non-wifi model) last year. The z590 TUF Gaming Plus (there is only wifi model available) is nearly $100 more. The Prime Plus z490, the MSI Pro z490 are other more affordable z490 boards.
Note that some z590 boards might not provide you with use of the pcie4 nvme slot even with a pcie3 ssd and a 10th gen chip. It is wired to the CPU directly and the 10th gen CPUs are not supported for that on those boards. All the more reason to look at z490 with 10th gen. You might buy a z590 board with three m.2 slots (yay!) only to realize one of them is useless with your 10850k (boo).
IF you do get a z490 board, it is important you pay attention to the onboard NIC. If it is intel i225-v 2.5gb LAN, be wary. The b1 and b2 steppings of that NIC have known flaws that are only partially mitigated with firmware and driver updates since release. Many of these boards don't seem to have the b3 stepping that totally fixes it and many people buying even recent shipments are still getting b2. It appears all the z590 boards do have b3 stepping, so no worries there. I specifically chose my z490 TUF board because it has the tried and true i219-v 1gb Intel NIC. I don't have 2.5gb switches or networking gear, anyway.