Someone within the last week mentioned on VU that mods were created because of "junk" like Egos. Sort of a joke, but not really.
There's a common progression of vaping. You take the cheaper/easier ways out until you can't take it anymore and buy better equipment. Sounds like you're at that stage. Try not to look at it as money wasted. You're learning as you go, and more importantly, not smoking as you learn.
Granted, getting a mod with a removable battery and a decent rebuildable atomizer is more expensive, but it's a way better experience. Or hey, keep buying coils. I freaking hate Kanger, but I'll readily admit that their new/round SSOCC coils last a loooooong time compared to their older versions.
Just two suggestions:
--Yes, buy a mod that accepts an 18650 (a legitimate Samsung, LG or Sony batt ONLY).
--Think about always having backup hardware on hand, so if something breaks, you can keep vaping. As
@DevAuto succinctly points out, "You don't want a single point of failure."