gjason

Note that BTech and Radioddity both have "store fronts" on Amazon; don't know if those are handled by other companies behind the scenes or are actually managed by the named firms.
And yes, my DB20G shows a rather drastic slope on output power: 22W in the (unlocked) 150MHz range sliding down to just under 12W on GMRS 467MHz repeater inputs (and 13.5W on the 462MHz simplex channels).
 

You can also buy from the store on this myGMRS.com website:
https://shop.mygmrs.com/

The biggest issue with gmrs gear is most of the better (and approved) gear seems to be one off to different vendors, which is why you won't find a ton of ability to cross shop prices on the same model outside of Midland.
Buytwowatradios.com is well regarded, as far as I know, and I've had no issues with the few orders I've had from them (have the 805g on the banner ad, another wouxun, and a couple other bits including antennas. For the Btech gear, they're the sole source on that. Radioddity.com has a couple options, and one (db20g) is a twin to the anytone at779uv, which I've only seen on amazon. A few members have one version or the other and are happy with them (myself included, with 2 of the anytone), though one member has one showing lower power out than it should, so maybe some quality control issues.
 

Should probably point here: https://forums.mygmrs.com/guidelines/
The other link was from before a pretty big site/forum upgrade, I suspect things have shifted around a bit. They're also in the menu in the top right, under the "browse" submenu, at least on mobile view.

I downloaded the GMRS img file that was posted a few months back.  However, I have a question...

Is this RPi image really all that different from the ones used by Amateur Radio's Allstar image or, are there just a few network related parameter changes in key configuration files?

I ask, because after recently building an Allstar repeater with the RPI 3B+, it seems a relatively minor effort to change the network servers in the config files from a working Allstar config system to those used for GMRS.  Seems like duplicating/cloning a working image and simply changing the required parameters rather than start a new build from scratch would be easier.

Just curious.