The low availability of the Ryzen 5 1600AF has actually made it a worse buy than an R5 2600. So if you can find a R5 2600 for $120 or less, consider buying that instead of the R3 3100. Although the R5 2600 is $20 more, you get 2/4 more cores/threads, about the same performance in single threaded task, but better in multi-threaded tasks overall and it's more "future" proof for games that will run better with more than 8 CPU threads.
If you prefer having the faster single threaded performance of the 4c8t R3 3300X compared to the R5 2600, that would be a better buy now for gaming than getting the 6c12t R5 3600X at $200-210. The R3 3300X has nearly the same performance per core as the R5 3600X and sometimes a bit better.
I personally would wait until Ryzen 4000 and Intel 10th Gen Core series are released and reviewed before buying new parts. Unless you need something right now, you will likely be able to get a much better deal in 2-4 months on a Ryzen 5 3600X or R7 3700X with the price going down the closer you get to the end of the year to probably $150 and $200 by October or November depending on stock of Ryzen 3000/4000.