The Eleaf iStick Pico landed in the 21700 version for $29.95 and available in 6 colorways. Also available with a 21700 cell (but shipping options might be restricted then) or in a kit with the Ello tank & the 12700 cell.
This mod is worth a look! Loved the 18650 version.
PS: 3F has it for $29.99.