I purchased a case and that is what I recommend. Each bottle is enough to fill the 4-inch portals twice. You will need a minimum of two just for the initial break-in period to purge any and all metal particles from the fires and second runs. Then if all is clear change about every 200 miles. All according to the Portal Experts at SuperATV. That way you have enough for the first year without having to order again.
Second time Portal Blood changed. First two are from rear and then the fronts are much cleaner (most of the driving was 2-wheel drive). Note: When draining I poor an once or two of new fluid in to purge as much of the old oil as possible you can see the new oil especially in the rear samples. I think one or two more times of draining the fluid after each run will complete the purge process. Most of what you see are the bubbles in the Portal Blood reflecting the sunlight.
Are you going to add shocks for our Talons, there are some companies out there but Alka seems to have the corner on the top end shocks. I would love to see an American made shock at that quality level -- monster price tag for them. What are you using on your vehicles?