Your post really captures some of what I'm talking about. Do I collect tagging errors? No. Do I want the option of detecting tagging? Well, yes. If you're all about the tags, then I can definitely see the need for a better unit.
The little cheaper ones may be penny-wise and pound foolish, even for very casual use. There are times when the cheaper <something> is fine. With UV lamps, I'm getting the feeling that the results will be much better with a better lamp. In this case, I'm sensing that I will regret buying a small portable.
From what I've read, the small ($25 $30) lamps are criticized for being weak, and insufficient for the task. Nor would I buy an $800 lamp; I don't have that to burn on a lamp, especially if I'm not specializing right now. For me, the $100-$200 range would probably be the sweet spot. That's not cheap, but if it can deliver the results, that would be worth it...one day...