There's a modification for this, at least on some of the Boss pedals with the original LED setup -- it should be around here somewhere if you do a search (probably in the Technical forum).
Nice find, I paid about double that. But I also got the box and manual. The momentary led is the way it should be, it isn't broken. The pedals are known to be noisy, so my reason for getting it was to add to the collection. If you want something quieter go with the GE-7.