If you are looking for a tube mod in your price range you can do much better than the Vamo. The Sigelei Zmax telescopic V3 or V5 or the solid tube V2. These offer solid stainless steel one-piece 510/eGo threading and removable top caps. Soft threads on the Vamo are famous for wearing out. The Sigeleis are shorter in overall length than the Vamo and have durable brushed stainless steel tubes that aren't fingerprint magnets. The Vamo is better than the Innokin iTaste SVD, though. That one has been plagued by bad buttons for the last several months.
The V3 and V5 telescopics offer the best battery versatility. Overall length varies from 100mm for 18350 to 127mm for 18650.
It's hard to beat the AW 2000mAh 18650 to start with for any of these rigs.
great deal on a Sigelei V5:
Desert Vapes V5
This dealer offers 90-day vendor warranties on V2 and V3:
Varitube
Photos at web sites are often out of date. This is a new Sigelei Zmax telescopic V5 I bought from Desert Vapes less than a month ago. It features a metal button and laser-etched logos. Sigelei is under the fire button, CE on the battery cap.