Are you looking for flavor and nic, and "simulating" smoking, or looking to blow clouds (lots of vapor). I used to smoke but changed to vaping and I'm what you would call a MTL (mouth to lung) user, sort of like puffing on a cigarette. I'm not really looking to blow out lots of vapor/smoke. You really only need a high wattage like the RX200 for low ohm, more complicated coils, and generating lots of vapor (not that you'll never use a high wattage in the future, but probably not quite yet).
There are lots of affordable options in the 75W range, which falls within a single battery solution (replaceable battery such as an 18650). You can look and an eLeaf Pico or Coolfire IV 18650, both single replaceable battery mods rated to 75W (but realistically, no higher than 45-50W with only one battery). Affordable tanks can be found either with factory made coils, or build it yourself. For factory coils (the easiest starting out) Aspire Nautilus coils and tanks (which includes the Triton mini) are considered an excellent solution. Other affordable tanks like that would also include the CeroTank (uses smaller Aspire BVC coils).
All those tanks are compatible with the RX200 as well. One advantage to the RX200 is that with multiple batteries and MTL lower wattage use, they'll last for a long time before needing recharging. But if you want something smaller and easier to carry around, something like a Pico or CF IV can do the trick. The great thing is that for the moment, there are lots of choices. Unfortunately, with new FDA regulations set to kick in in August, new products will not be coming to market, and things may become less available. Te best way to future proof is to be sure any mod you get has a replaceable battery (all Li batteries eventually cannot take a charge after ~300 charge cycles) and that you either stock up on factory coils, although I expect plenty to remain available for some time, especially something like the Aspires which are popular in the vape world, and prepare yourself to eventually make your own coils, which is a lot easier than it might appear at first.
