Here are the cheapes…

HP OMEN 45L Overview
This configuration of HP’s OMEN 45L is currently the cheapest RTX 5080 prebuilt gaming PC you can buy. With a price of just ~$2,300 it’s on par with about how much you’d spend to build your own RTX 5080-based system.
It comes with an Intel Core Ultra 7 265K, an NVIDIA RTX 5080 GPU, and 32GB of DDR5 RAM. That core combination is good enough to allow you to max out most games on a 4K monitor, or achieve an extremely high framerate at 1440P resolution. For this setup (and all of the RTX 5080 PCs on this list), you’ll want to pair it with a high refresh rate display to take advantage of the higher average framerate.
The Core Ultra 7 265K isn’t the best gaming PC and it is on a socket that likely won’t receive any new CPUs—so there probably won’t be any upgrade options in the future. However, if you’re planning on playing graphics-intensive titles at higher resolutions, your CPU will matter less than your GPU and, in that case, the Ultra 7 265K won’t hold you back too much.
But, if you play CPU intensive titles, you may want to consider spending a little more to get a system that has an AMD X3D chip in it, as the extra cache those CPUs possess allow them to provide a lot more performance in those kinds of games.
This system also comes with a 360mm AIO CPU cooler, a 2TB NVME SSD, and a mid tower case that has a tempered glass side panel.
Overall,this configuration of HP’s OMEN 45L series doesn’t come with the perfect configuration of components, but it is pretty darn good and if you’re looking to spend as little as possible, it is currently your best option.