So, lets get some things out of the way first.
There are many types of lasers. In order of expense (not every type, but consumer uses)
Diode -> CO2 -> YAG -> Fiber
The first two, Diode and CO2, are what's in your price range. Unfortunately, they will NOT directly etch metal. The wavelength of light they emit just doesn't jive. You can use a spray like Cermark to mark directly on metal, but again, no direct ablation of metal.
Going into YAG/Fiber laser sources starts getting way outside your price range ($25k+).
I usually suggest most people buy a K40 type laser and do some small mods, or a slightly bigger machine with a Ruida control if they can. See this thread below