So what's the deal with cell phone companies.

My wife and I have Google Fi service. $35/line plus $10 for every Gig. But...you get refunded for any data you don't use. For example, I pay up front for 2 GB but only use 1.5 GB, I get $5 off next month's bill. I think you no longer pay after 8 GB but I rarely go over 2 with wifi at home.

Right after I bought a Pixel 3a XL from Google for $349, Best Buy had them for $200.

If you go through the online, you'll probably get the extra 8GB.