Best Buy has 128GB Samsung Galaxy S10 Unlocked Smartphone for $499.99 when you Activate on Verizon, AT&T or Sprint. Shipping is free, otherwise free store pickup is available where stock permits. Thanks mbsmith76 & NotThatCup
Can't find how long this deal is good for. Props to jayz09 for posting this earlier, but it went inactive, likely as BB posted it early. I have zero issue with mods closing out this post and reactivating jayz09's now that it's no longer expired.
[Updated to 256GB model per NotThatCup, thanks for the heads up!]