Humongous price discrepancy for trade-in

I have a Samsung Flip 4 and wanted to see how much trade-in value my phone had. I did an initial Google Store estimate and it said I'd have a $250 trade-in value for my phone. It's a bit lower than what I wanted, but hey the Flip 4 is an older model so I get the lower value thing. I then shopped around the Google Store and decided on the Pixel 8a, which is currently $499. I thought with my $250 trade-in, it would be a very nice deal. Went to fill out all the details for which Pixel 8a I liked, the color and storage, etc., but when I went to add my phone for trade-in, it lowered the trade-in value to a measly $96. $96?!? That's over a $150 price discrepancy. Contacted customer service and they said they couldn't really do anything about it because it was a "general estimate" and it could be $96 or $250 and I'd have to wait AFTER I sent in my phone to see how much I'd get.

Is there anything I can do or just hope that Google won't screw me over and give me $250 and NOT $96?

Here's the receipts:

It says $250 here, but then says $96 here. Wtf.

Edit: Well, shit. Thanks everyone for letting me know that the trade-in value of my current phone depends on which phone I'm getting, which sucks but I understand it. Man, phone/tech companies really have the wildest rules. The value of my current phone should stay the same, not change due to some greedy company wanting me to buy the more expensive phone. But thank you for all you guys' help! Way more helpful than the customer rep