This first one is a Bestem top box. It came through Amazon with free delivery for under $85.
Here's the link to the Amazon ad:
The build and quality of this one is not as good as a Givi box, no question. Don't expect it to be.
Having said that, you get a lot for your money with this one. I don't know the volume of this one but I'm guessing it's in the 35 ltr range. It will hold one full face helmet and a rolled up jacket. It's not quite big enough for two full face helmets.
The box comes with an adapter plate to attach to your existing rack. With a bit of filing to stretch out a couple holes, it lined up with the slots in the stock plastic luggage rack on my 2015 V-1000. It would be more solid on a bigger rack (which I have on order) but it is actually pretty good as is. The box does come with a built-in LED taillight, which I have not hooked up and probably won't. The box has a wire from the light and a grommet in the bottom of the box for the wire. It also comes with a length of wire with bullet connectors on each end to wire it in. I like to be able to pop the box on and off quickly and easily and the taillight would entail a plug of some sort hanging from the box for power. If it was never or very seldom going to be removed from the bike, I would hook it up.
The lock on this box is not as nice and secure as a more expensive box. It is not as easily visible that the box is latched and locked as it is on more expensive boxes. It is a very good idea to check every time you close to make sure it is secured so it doesn't bounce open or get pilfered.
There is an optional liner available also from Amazon for it that costs an additional $35. I did not buy it but I see that there are exposed screw heads inside the box that this liner might help cover and protect your nice helmet from scratches.
My bottom line here is, if you have less than $100 and want a fairly solid top box, this one works. If you can afford a Givi, do that as the quality is definitely better.
Here is the included metal adapter plate attached to the rack: