Movie moguls: british american tobacco’s… [eur j public health. 2006] pubmed ncbi
If I could expand on this a bit, it may help.
The reason is physical weight. The process for production between big and small cigarretts or regular and plus size clothes is basically the same, and under the same cost control processes. Therefore, burden and production cost the same the final factor is end product weight and physical make up in assessing cost.
When it comes to apparel items, they' re often times ordered in large quantities where weight differential between small and large sizes start to become significant factors in freight cost.
Plain and simple? It cost more because they' re heavier. Much heavier when shipped in large quantities so what you end up with is a higher end user price on the single item despite the shirts being almost identical.
This is easily overcome in cigarrets by reducing weight of packaging, filter weight, etc.
My assumption because I don' t know, is that 100' s are infact a better value, however as a smoker, they don' t offer the same user experience and also are generally meant to last longer which is basically preference.
Hope that helps clarify.