Unfortunately the first device from this partnership is unlikely to be cheaper than the a series Pixel lineup. The GrapheneOS team already confirmed it will have a flagship snapdragon SOC. Have you looked into used a series Pixel devices? The 8a can be had refurbished in the low $200 range, and it will have software support for 5 more years. The 9a can be had for about $250 and will receive 6 more years of updates.

Honestly, $400-$500 for 7 years of support is a killer deal. 5 years ago the only manufacturer to give a meaningful amount of support was Apple, everyone else was up to 2, even for flagships.

But I completely understand your situation, especially if you're trying to be fiscally responsible and NOT get your phone on a payment plan of some sort. The 7 years of support means you might be able to find a 2 year old Pixel for below 300 though? Unless they don't depreciate fast enough for that.

Bruh Android devices used to only get 2 to 3 years of support at most not that many years ago. 7 years is a MAJOR improvement.

I just picked up a Pixel 7 for 200 from swappa

I didn't like the look of the batteries in the pixel watches. I actually have a Huawei watch (yeah, I know) and it's great. Turns out, when you're subsidised by the Chinese state you can make a good product that costs less.

for something that they themselves admit would likely only get around 7 years of support.

Do you know of an android device with longer support than 7 years? The norm is 3 years.