Ryzen 5 5600X $299
Ryzen 7 5800X $449
Ryzen 9 5900X $549
Ryzen 9 5950X $799
All prices in USD.
Note that these CPUs are very sensitive to RAM - even more than the previous generation and you can get a fairly decent performance boost if you pick your RAM correctly.
I think the sweet spot here would be picking either
2 x Dual Rank sticks (memory chips on both sides of the RAM) = 2 x 128-bit = 256-bit total
4 x Single Rank sticks (memory chips on one side of the RAM) = 4 x 64-bit = 256-bit total
But then you need to research and see what memory topology your motherboard has as it would be more efficient to go with one option over the other depending on that. Then there are the timings to consider and all that... lots of variables, but if you get everything right, looks like you can see up to 10% performance improvement in games or even more.