Buyers often negotiate the unit price and leave the pack format to the end. In low-inclusion peptide work the format can matter more than the per-gram price, because it decides how accurately the active enters the batch.
A weighing example you can recompute
Assume a brief fixes the active at 0.05% in a 100 kg batch. The charge is 50 g. A 1 g weighing error is 2% of that charge. On a 50 kg batch the same 1 g error is 4%. These are stated assumptions, not a recommended inclusion rate, but the arithmetic shows why we ask about batch size before proposing a pack format: the smaller the charge, the more the weighing method dominates.
Why sample and bulk prices are not linear
A 1 g sample and a 1 kg order do not scale by a factor of a thousand. Small packs carry proportionately higher filling, labelling, QA release and documentation cost per gram. A quotation that lists sample and bulk as separate line items is usually more transparent than one blended price.
Pack choices that affect your process
Amber glass protects light-sensitive actives; foil pouches suit bulk powder; a pre-dispersed aqueous premix removes a low-inclusion weighing step entirely. Ask whether the batch number on each pack links back to one COA, and whether split packs from one batch can be supplied for multi-site trials.
What to put in the enquiry
State the sample quantity, expected repeat volume, pack sizes, destination climate, and whether you need one batch split across several packs. Ask which documents accompany a sample and which accompany a bulk shipment, so a sample approval does not turn into a documentation surprise later.