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.
The iPhone 11 Pro and iPhone Pro Max are extremely expensive. The iPhone XS starts at $999 and that's the cheapest model Apple is selling. The iPhone 11 is cheaper, but it's still $700 for the base model.
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.