A grenade launcher, or a bazooka round is just as effective and a LOT LESS MONEY!
Ummmm do you know how long it's been since the Bazooka round actually saw combat? Like maybe the Korean War. It's since been replaced by the 90mm recoiless rifle (which was in my active duty unit -- the last unit in the army to have those) and then later replaced by a generation of fire and dispose rockets like the LAAW series and later the VIPER and who knows what else by now. If the technology is reliable under combat conditions then any expense is worth it!