beet root extract is dirt cheap, just up the dose, i've been including 15g beet root extract with my pre work out stack and it's amazing at that dose
Even at that monster dose (15 grams), it only provides a total of 150-300 mg of nitrates. 300 mg is OK (pretty much at the bottom end of what is considered an effective dose for pump purposes), but 150 mg is considered a very small dose--less than the minimum recommended amount for enhancing bloodflow.
Sodium nirtate is MUCH more cost effective than beet root extract. A 1,500 mg dose provides roughly 1,000 mg of nitrates, which is 3.5-7X as much nitrates as aq 15 gram dose of beet root. Besides, who wants to consume 15 grams of beet root? If you are taking capsules, that is like 15-30 caps...and if you want to get the same dose of nitrates that is found in 1,500 mg of sodium nitrate, you would need to consume 50-100 caps. Even if you have pure beet root powder, taking a 50-100 gram dose is massive--roughly the equivalent of 2-4 scoops of protein powder...not to mention it would cost WAY more money than a 1,500 mg dose of sodium nitrate.
The bottom line is that beet root extract is an inefficient, non-cost-effective and out of date way to consume nitrates.
The only reason ANY supp company includes beet root extract in their pump products is because they want to be able to say that their product contains nitrates, but they don't want to pay the ridiculous patent fees (courtsey of patent trolll, Ron Kramer) for pure nitrates. If Ron Kramer (i.e. Thermolife) didn't have all his ridiculous (and sometimes invalid/illegal) patents, not a single supp company would be using beet root extract in their pump products. These companies know that the amount of beet root extract in their products won't do jack, but include it for marketing purposes. They are counting on the FACT that the majority of supplement buyers aren't aware of the beet root extract to nitrate ratio, or even the amount of nitrates they should be taking for pump purposes...and are instead simply happy that the product they bought contains nitrates.
Taking beet root extract in the hopes of consuming an optimal dose of nitrates is like consuming a 5 pounds bag of oranges in order to get a 1 gram dose of Vitamin C. It just doesn't make sense when we have pure (and less costly) nitrates readily avalable.