DuraVent gives a .016 inch stainless inner, a .018 inch galvanized outer and reduced clearances.
Using it
Each elbow costs draft, so keep the run simple. Fix joints with screws as your manual directs, and keep clearances from walls and ceilings.
Questions this guide leaves you with
Does it fit other pipe?
The listing says DVL pipe, and factory-built chimneys such as DuraPlus and DuraTech.
Does it hold the 6 inch clearance?
The listing says so. Check the manual.
The price on Amazon.com
This model is listed on Amazon.com, at ≈ $77 at the last reading. Listed is not the same as in stock: availability changes daily, and the buy box shows the live price.
At $77, it sits +133 % against the $33 median of the 10 models in this category published here.
Sources
Specifications: the manufacturer sheet for wood heating equipment and the matching Amazon product page. Prices, ratings and availability: read on Amazon.com from a New York address. Every figure on this page names its source.
The price beside each product is fetched as this page opens, and it is the only figure here that is current. Any amount written into the prose was read once, on the day that sentence was written, and nothing has refreshed it since.