Reasonable PC upgrade

Current build :
- Ryzen 5 5600G
- RX 6600
- B550 motherboard
- 650w PSU
- 16gb DDR4 RAM CL16 3200mhz

Replacing the motherboard for an AM5 one is obviously out of the question, I won't get into DDR5 territory. So I want to replace only the CPU (sticking with AM4) and GPU.

GPU
RX 9060 XT 16gb , 450€ brand new no sale. Hard to find one used at current time.
I think I could get 170€ (top) out of my RX6600.

CPU
I'm hesitant on this one. the 5600G is limited to PCIe gen3, but the benchmark comparison with PCIe gen4 for the RX 9060 XT show negligible gain.

If I upgrade the CPU it would be a Ryzen 7 5700X, 150€ used. Not a 7800X(3D) cause negligible gain and higher TDP.
I can get ~90€ out of my 5600G.

RAM
I do find some used 16gb DDR4 (CL16 3200mhz) under 100€. As long as the specs are the same it doesn't matter if it's not exactly the same model ? Definitely dubious about those listings.

What do you think ?