As I've mentioned elsewhere, the main reason why I have difficulty giving any weapons but Guns a fair chance is silencers. Once you get your hands on even the puny Silenced .22 pistol, your caps and equipment problems go away. Generic Powder Gangers can be killed and their gear taken with no reputation or karma loss. Upgrade to a silenced Varmint rifle, and you can harvest armor-clad NCR and Legion soldiers without alienating their factions. With Jury Rigging, the cap gains are gigantic, since NCR armor worth 300 caps can be used to repair Combat Armor, Reinforced worth 8000 caps, and Service Rifles worth 700 caps can repair LMGs and Marksman Carbines worth 5200 caps- and the investment is minimal. Hell, I've been known to assassinate all NCR soldiers at the Mojave Outpost just to stop them from stealing the food and drink from the shelves- and not a point of NCR reputation lost.
On the other hand, with Energy Weapons there is no option for silent assassination that I can see- and that is the weapon group in which supply issues are the most acute. From time to time people mention that "some" Energy weapons are silent, but I'm yet to hear which ones. Grenade-in-pants is a deficient substitute- harder to pull off, you can't use it in a crowded room and the caps-per-kill investment is much more significant. Plus there's few non-Fiends wielding Energy Weapons.
I think there should be some sort of silencers for EW OR an anti-cheating measure against over-exploiting silencers.