I have 3 fiber lasers, first one I got from Triumph (I also bought a big 1390 glass C02 from them in 2013), 2nd was an Ebay machine, bought in Dec 2018, liked it so well I bought another a month later.
Fiber lasers are very simple machines. I've been finding out lately that pert near everything about them is interchangeable. My Triumph came with the good ol/ big M85 lens mounted to a 'good' scanhead, both Ebay machines came with the simpler and much smaller M52 lens, mounted to a 'budget' scanhead. I've bought 3 cheap M85 size lenses, and one M52 lens- as to the scanheads and M85 v M52, I've found NO difference in engraving quality amongst any of them. There may indeed be some aberrations in how they engrave but all of them, even my new 420mm lens which focuses nearly 19" from the work (think about that for a minute!), can engrave .025" high characters that are nearly perfect. (How can the mirrors move such a small amount that they're able to very accurately steer the beam to make perfectly readable 3 point lettering 20 inches away, and at blazing speed?)
Anyway, my point is, the more expensive pieces don't seem to be much if any better than the cheap stuff.
Back to interchangeable- I've been swapping scanheads between the Triumph and one of the Ebay lasers, because the Triumph is a portable, and can't make use of any larger than a 300mm (220mm work area) lens. The 420 isn't available in an M52, not sure but I don't think they're capable because of their size. But I found the scanheads don't care which machine they're connected to, the only issue is, which is normal, is that every lens must be fine tuned to the machine it's connected to. And my Triumph came with a proprietary control card and EzCad software with external dongle. The newest version of EzCad is far and away better than what I had, but the only way to upgrade was to change out the controller. $318 and 4 days later my new BJJCZ card- cheapest I could find
- came. It's much smaller than the old card and had one less plug (the Triumph card is setup to allow for conveyor and other 'flymark' use) but didn't matter. Screwed the new controller down with one screw, plugged it in, and the only problem I had was I had to uninstall the old driver because it was looking for the OLD dongle. Once done and the new driver installed, the new 2.14.10 EzCad installed and that was that. Dialed in the laser's settings and I was off and running
Everything "inside the box" is fairly generic and easily replaceable. If you're the least bit handy with hand tools and such, these things are not that tough to fix and maintain yourself.
IF you decide to check out the Ebay route, check out the sellers, be wary of sellers with few sales, some of those guys just plain won't be around after the sale. FWIW, my ebay machines have a "Vevor" brand, and there's a lot of Vevor stuff for sale on ebay, mostly commercial/industrial type equipment, and I've had good luck with these machines. I've sent a couple of emails, the seller has emailed me back. Received in 3 days, and usually their ads state the product is located in Anehiem CA.
If you'd rather not chance it, I'd give Triumph a look, they, and their machines have treated me well...