Don't Wait If You Don't Want to Spend
If you don't want to spend a ton of money on your next phone there's no sense in waiting around for the 2020 iPhones.
According to Ming-Chi Kuo, the iPhone's price points won't change much in 2020. There's a chance we see a slight bump due to the arrival of 5G, but Kuo doesn't expect anything major at this point.
If you can't or don't want to shell out $700-$1000 (or more) for your next smartphone, you'll probably want to look at other options.
There are a slew of inexpensive iPhone options to look at and there are also a ton of cheap Android alternatives on the market right now.