Sorry to bring up an ancient thread lol, but I just got the Monster Trumpets practically in new condition for £32 on eBay and they're awesome. Took some tip swapping but they are way better than I thought they were going to sound. They actually sound very much like the Final e4000, but more cohesive, less bass bloat and with better resolution, especially on the edges of the soundstage. Would they have represented the same value if I'd bought them at £242 when they first appeared... probably not, but if I'd paid £100-150 they wouldn't be out of place with sets at the similar price these days.
Love the tip collection... they're going to be great with other sets in the collection