I appreciate posts like this, but i think I'd gain more from it if there were specific things to look for that tell a buyer what to look out for. Essentially a custom product could very easily be someone ordering different products from a catalogue and assembling them together. There's varying degrees of "custom" so it all depends on what you're looking for.
Either way, I'll second iJay's comment. Careful with your words as it can bite you in the ass sometimes.