Last February I purchased on eBay a Markbass Little Marcus 800 for $550. I thought I got a decent deal because the unit's relatively new, manufactured in 05/2018. It's had very little use, as it's just a back up & I've sporadically noodled with it. A month ago it came up with an intermittent shut down problem. The LED lights stay on, but no sound. I'm aware of the fact that Markbass has a two year transferrable warranty, &he authorized warranty repair center in Arcadia, CA did their best to get me an RA. Ultimately I have to provide documentation it was purchased through an "authorized dealer". I was surprised to learn of Guitar Center/Musician's friend's exclusive contract. The bottom line is that it's incongruous that the unit could have been released into the world by any other means. I'm certain he serial number is traceable, all that takes is cooperation from a corporate executive overseeing both GC & MF (good luck Charlie, I have no idea who to call & possibly sue in small claims court). Yes buying used is risky, but knowing how new the amp is gave me a sense of false security. Out of shear frustration I just ordered a Mesa Boogie WD-800 hybrid. It has a 5 year warranty, & a customer service department in the US that you can call. & they will respond with a sense of accountability. Now I'm kicking myself in the butt for not doing more research. Never again will I have anything to do with Markbass, Musician's Friend or Guitar Center.