I had one of the Smok pens do the same sort of thing to me. At first I thought it was the coil, cause it worked at first. but then it started doing it with the new coil. So anyway, I contacted the store and was able to send it back for a replacement. I opted for store credit and I was going to get the Species by Smok, but I saw the Sigelei Sobra for like $20 cheaper and great reviews. There are a bunch of kits in your price range, just check out some reviews first; Xlum, Armour Pro, Vaporesso Swag or Revenger, Eleaf Lexicon and oh this one seems interesting - Innokin Plexar