But both of those are trivial amount for most people. The typical 4 foot tank has 2 halides, bulbs run $40-$80 each for pretty much every single hobby bulb out there. Electric costs me at most 10 bucks more to run 2-250 watt halides on magnetic HQI ballasts. Heat is a total non issue for me. So my monthly davings are about $15-$20 were I to switch to LEDs. But that is also assuming zero LED failures( on fixtures that are obsolet- have fun with that one) or driver failures over the course of its life.
For those truly saving 100 or more a month and solving endless heat problems, they are a great choice. But ot get LEDs for saving a few bucks a month in this already excessive hobby is ridiculous. I've thrown away more PVC fittings in this hobby than I would save in one year of LEDs