Is the $200 budget for the device alone, or is it meant to include the mod, topper, batteries, charger, ohm meter and voltage meter all together? If it's for everything combined, I would suggest looking at some clone options from Hcigar, Ehpro, or Infinite. Those companies seem to be the highest quality clones around. One of the most common clones that people seem to be happy with are the Hcigar Nemesis or the Infinite Stingray. I guess figure on around $40 for the clone if purchased from a US vendor? Check out 101vape.com
Do not go cheap on the batteries however. I've heard great things about the Sony VTC4 and 5. Also, don't go too cheap on the charger. Some of the lesser quality ones can either under charge or over charge your batteries, which will shorten overall life span. The Nitecore i2 or i4 generally seems to be reasonably priced and work well.
For toppers, for around $30ish I highly recommend the Kayfun Lite Plus from Ehpro. I think these are the best Kayfun clones out there. It's like a rebuildable bottom coil tank. Aside from building the coils, they are generally less of a hassle. Less leaky, but with better taste if the build is right. If you don't want to rebuild, then I suggest looking into cartotanks. You'll want a glass tank, with metal end caps and high quality o-rings to ensure a tight fit for a cartomizer. IBTanked has some great quality tanks for around $25. $5 more and you can get them custom painted. Never had an issue with their tanks. Never had a carto slip out either. Go to their complete tank section, and the site walks you through buying everything you need for one. For a mech mod, get the lower res cartos.