I fully respect Boker (German), have no experience with Boker Plus, but do have a Boker Magnum. It was about $15, and is a liner lock with a plasticized wood handle (they make dozens of similar knives).
Brief review of a Magnum: The handle is quite nice, and I would have no complaints even if the knife cost much more. The blade is thin, made of basic stainless steel, had ragged sharpening, and a sandblasted finish. It is exactly what you would expect on a low priced knife. The liner lock is a bit short and it springs 100% across with a little gap, so it has a bit of blade play. I tightened the torx pivot and it took away most of the blade play but not all. It is worth $15 but not a lot more.
Fine company, just check out the model number at a few places to make sure you are buying from the right product line.