Don't throw your old coils away. Just put them aside in some container somewhere.
Eventually you may get interested in rebuilding them, not necessarily for the cost. You can get much better performance from a head with a well-made recoil than with the stock factory heads; I rebuild mine for performance, not for savings. Well, also so I'll never run out of coil heads! Well, also because I am a tinkerer! OK, I admit it, I'm a cheapskate!
Rebuilding a head is not very difficult.
-Once you rebuild a coil once or twice, it becomes routine. I like rebuilding mine for performance also. I prefer a warmer vape for tobacco flavors. Using AWG30 wire, it is very easy to end up with around 1.8 ohms, which is IDEAL for my vaping requirements. YMMV!