A lot depends on what resolution you are gaming at, and what kind of games you are looking for more performance in.
At least in the US, you could get a 6-core, 12-thread Ryzen 1600 AF (the slightly faster version with the smaller "Stealth" cooler) for as little at $85 on Amazon now, which could provide somewhat better performance than a 1200, especially in heavily-multithreaded titles. Or there's the Ryzen 3600 offering around 20% higher CPU performance than a 1600 AF for around $175. So, it might be possible to get both a CPU and GPU upgrade without breaking the bank.
As for those cards, are you refering to the 5700, or the 5700 XT? The 2070 is a bit faster than a 5700 (non-XT) by maybe around 10% on average, but generally costs a...