OK, I'm actually sad to see this not mentioned as a cheap and quality dripper to start with: the Igo - L. Single coil, fair-sized deck to build on and a good dripper for a beginner.
A few things though when asking for RBA suggestions:
1. Know what kind of connection/ threading is on your mod. Most are 510, but there are adapters for nearly everything. Regulated or mechanical does not matter with an RBA since you control the resistance.
2. Specify if clones are acceptable as suggestions. The "real" Russian is well over $100 from most retailers... and SvoeMesto makes the original Kayfun (even if some clones use a similar logo).
3. Try to add something about how you vape. Are your always on the go - drippers are hard. Do you vape multiple flavors a day or do diy - drippers are better than big
tanks.
Finally, just a note on the Kayfun/Russian theme. Yes, they are a fantastic vape but can take some fiddling to keep from leaking due to a touchy wicking issue. Also, the coil tends to be touchy if you are not used to getting the post screws *perfect*. I would suggest picking up a cheap dripper for practice (ie: igo-l; evcigarettes.com for around $10) and a bunch of wire (kidneypuncher.com 250ft for around $15). Those 2 things and a multimeter/ohm reader will be a life saver.
If you have a smartphone check out the Vapers Toolbox app. And remember that your ohm reader can be wrong so test that coil with a meter until you can repeatedly hit your target resistance (1.2 ohms and above for most regulated mods to be safe) or you stand a chance at destroying your mod... or worse.
Best of luck in the RBA world and happy
vaping!