Not to stir up this debate again, and definitely not to cast any aspersions on other manufacturers, but it does cost surefire some time and money to get these certifications, as well as others they get for some of their products.
Whether that's "worth it" to you really depends your application. For hiking around in the woods at night - I'll be honest, I've never stopped to think about whether or not my flashlight would interfere with my GPS. So for me, not so much.
If I were operating a piece of field artillery, or flying a commercial plane, or otherwise engaged in an activity where something *really bad* could happen because of electromagnetic interference, I think I might pay more attention to that!
Of course like all certifications, nothing is really 100% sure. The FCC does have tough standards and does enforce them. They make mistakes too though - for example the original HD broadcast station in DFW, WFAA, had to temporarily shut down it's test HD broadcasts years ago because the HD signal shut down the wireless heart monitoring equipment at nearby Parkland Hospital!
Anyway, I guess you pays your money and you takes your chances!