The only prebuilt coils I used were those that comes with spare parts...I do not understand how people are not able to make their own coils but have no problems installing prebuilt ones.
For me... because of my poor vision it is much more challenging to install coil than to make a coil... particulary on RTAs with very small deck where you have to wrap coil legs around a screw head (Doggystyle,Dwarv)... sure I am not making any exotic coils but to make twisted wire with the help of drill you do not have any special skills... just look on any you tube video and in less than five minutes you can make enough twisted wire for a dozen or more coils... if 60 years old can do it you can also do it... Making coil with coil jig is easy and effortless ... in 15 minutes I can make a dozen coils...
Is it cheaper than drop in coils? Of course it is cheaper.... I was using Aspire Nautilus BVC coils ( $2 ) and Smok M2 Baby Beast coils ($3) and I liked them (BVC not M2).... but after 2-3 days flavor on them get muted and after a week they were unusable... at the rate of 2 per week I would spent $200 for the coils in a year... for 100 feet of Kanthal I paid $5 (shipping included)... I can make easily over 100 coils for just five bucks! Oh I forgot wicking material... but for $15 I have enough of it for many years.... I do not know how long coils I make last... after a week or two I change them... for different number of wraps, inner diameter or trying twisted wire etc.
It amaze me that so many vaping newbies are buying cheap vaping devices that have zero control of vape and spent "fortune" on drop in coils in a hope that this particular coil or mod will be better than previous without gurgling, spitback and burnt taste... and they will come to this forum asking for advice but expect that another device with just one button to push and with zero control will provide them better vape. I they really do not want to learn why asking people for advice for better vape... keep puffing that cigalike or other "blue" .... RTA tanks have the same problems like a drop in coil tanks but it is much easier to learn what makes good vape with RTA or RDA than with drop in coil tank.
I am also not buying that excuse I work 6 days a week and do not have time for making coil...it is the same excuse like those that on the way to work stop at Starbucks wait in line and pay $6 or more for something they could do it easily at home... some will have time to write 100 posts per week on this forum so they have no time to make single coil in a week
IMHO using RTA is not a rocket science and any adult can learn it in a few days...I bought my Siren after 4 weeks of vaping and had no problem making my first coil using just screwdriver... and I am not "handy Andy".