There really is no 'budget' upgrades available for E's. Now $15 will get you a 150 lumen bulb from Lumens Factory.
A logical solution is the single LED upgrade by a really smart fellow who makes dopin's called Tana singLED. At $80 they aren't cheap but he uses firmware with all kinds of setting easily available via 8 half presses to advance to the next combination of settings. Low/High to start, or high only, or all kinds of 3 or 4 setting combos going from lower to higher or higher to lower. Some have memory too. Heck, I think one setting deep into the available number like #17 is strobe. lol.
It's a nice brass module that should last as least as long as the light itself.