Right now, both Amazon and Best Buy are offering $100 off of the regular price, making it $299 and $429.99 respectively. That's not all though, because Best Buy will give you another $50 if you activate the device upon purchase, bringing the cost down to $249.99.
It's a solid deal for a mid-range device that's designed to have close to feature parity with a flagship. The Pixel 3a offers a stock Android experience with timely updates, Now Playing which tells you songs that are playing on the always-on display, the same camera and camera features as the Pixel 3 series, and more.
If that doesn't sound like enough for you, the Pixel 4 series is also on sale by $300, so you can get the Pixel 4 and Pixel 4 XL for $499 and $599, respectively. Interestingly, there aren't any significant deals on the Pixel 3a XL (Amazon has varying prices, as usual), and that could have something to do with how we're not expecting there to be a Pixel 4a XL.