The 2200g is only slightly less powerful than the 2400g. With such a large price difference, it would certainly be better value, but $400 is still extremely expensive. How expensive are the intel i3 8100s in your area? The integrated graphics aren't as good, and it might be even more expensive, especially if the motherboards cost more, but it is worth checking.

Just to be clear if you'd get the Ryzen 3 2200G for 400 you'd still need to get a motherboard and ram that fit with the new processor since your current ones wont work with it, so that'd still be quite a way out of your price range.
I don't have much expertise besides that in the Brazilian market either so I cant help beyond that bit of info.

huh... in Vietnam, an intel i3 8100s would cost about 100$, yup that's a real price.
i'm using a GTX 650 and it only costs 13$ tho, i'm not lying, those are not second-hand stuff too.