Cruise missiles can scatter. Maybe not enough to matter...
Hey, that rhymes!
Annoyingly the booby trap is only 240 in the trapped units hex. So, unless you use the advanced mech-hugs* rule to get into the same hex, or stand on top of some infantry or vehicles, you don't get 240. Units in the adjacent hex would only take 120 damage. I say 'only', but that is the same damage as the biggest cruise missile. I admit scatter happens, so that is a disadvantage. However, the Cruise Missile is slightly faster than the Celerity so that is nice. A Cruise Missile moves at about 5 map sheets per turn. A celerity 05-X at full speed moves 40 hexes, which is about 2.5 map sheets assuming clear, flat terrain...which is actually kind of frightening.
Anyway, there are probably other mechs that would give you a better bang for your buck (Ha!) than the Celerity. It may ONLY move 10/15, but the Scarabus has a 300XL engine in it, or you could rig up an intro-tech Spider with it's standard 240 for the same punch if you can stand to only move 8/12/8. The Cicada isn't bad either with its low-tech components and 320 engine. Of course, the king of stuff to blow up is probably the original Charger. It has that massive standard 400 engine which gives you the best damage you can get outside of a superheavy (which I guess you can booby-trap, but I'm not really sure). It's also dirt cheap, using nothing even remotely exotic, and if you drop the small lasers to fit the booby trap, it is about as minimal as you can get in terms of equipment you are wasting by blowing it up.
If you are only looking at BV the Celerity is, I must admit, a pretty inexpensive choice. Even the Ostscout K, the one with nothing but a TAG on it, is still twice the BV of an 05-X Celerity. You can get three little bomb-doggies and have BV change left over for the cost of the base model Charger. I know C-Bills are a broken/irrelevant metric in the game, but it still rubs me the wrong way to purposefully blow up all that cutting-edge tech! You want to blow up a bunch of intro-tech Spiders or Chargers, and I'll bring the marshmallows to roast in the flames of their wreckage, but don't blow up that lovely XXL engine!
* NOTE: There is no mech-hugging advanced rule...at least, not an OFFICIAL one!