i like the idea, since it could add some great fun.
But also it would add laming.
So, they should be expensive as hell, a absolute minimum of 5millions, but also a timer, of 10 minutes where you can't use it.
Why not put the bomb planting in a minigame?
Like 5 people driving cars and other 5 people planting bombs on them.
E.G.
Me, Hitman, Krayzie, Athene and FateTrip are driving cars and Shark, IMMO, 8Ball, AzTeC and Hellweed plant bombs vs us. Shark has to plant bombs to blow up MY car, IMMO to blow Hitman's car, et cetera.