Pricing scales predictably with volume — single vials run $45 or so for 100mg and $180 for 500mg, mid-tier buys of 10 units drop to roughly $38 and $155 respectively, and at 50+ vials you're looking at $32 and $135, which works out to about $0.32 per milligram at bulk for the 500mg. 2. For longevity or mitochondrial work this is actually better than reagent-grade NAD+ because teh 99.6% purity (checked by HPLC, our company have COAs for every batch) keeps background interference minimal in enzymatic assays, but don't use it for anything requiring aqueous stability beyond 72 hours — the lyophilized powder is what gives you that 24-month shelf life. 3. We usually have stock of both sizes (100mg and 500mg) in sealed glass vials, but the 500mg is easier to handle if you're reconstituting for multiple runs since you can aliquot it and store the dry powder at 2-8°C without worrying about freeze-thaw cycles. 4. Trust comes down to consistent specs — we've shipped roughly 2,000 vials this year alone and the lot-to-lot variation in purity stays within ±0.1%, which is tighter than what most small suppilers manage, and we'll share the SDS and TDS before you even order (just ask).