You could also consider getting a 5700X (£270) and a cheap B450 motherboard, keeping your RAM and getting a new psu.
The 5700X Has 8 cores 16 threads and is a very tidy upgrade.
The new AM5 socket is going to be DDR5 only so very expensive. Rocket lake is also going to be expensive.
Socket 1700 has the Some great CPUs too, I just can’t help but point out how cheap a B450 motherboard is.
You could then save up and get a 4080 in September, it really depends.
Your whole rig needs to be improved upon to play MSFS