u/Immediate_Course_538

I have an RTX 3070 and a 16 GB DDR4 memory stick, and I'm looking for a CPU and motherboard combo. My B450m motherboard died on me so I'm looking for an upgrade.
My idea is not to spend money on memory, but I will take any suggestions. My budget is between 300 and 500 euros, but I will try to keep it on the lower end. My location is Ireland.