Listing Buffs in the Trade Office - why the "lot" restriction?

[NosajDraw]

When you list goods for sale in the Trade Office, presuming you have the items to sell, you can select up to four lots to be sold.

However when it comes to buffs, you can, regardless of how many you have, only have 1 lot.

What's the reasoning behind this restriction?

[vigabrand]

i am also perplexed by these limits.

there seems to be no logical reasoning as to what can be sold in lots of 4 and what can't. also the new limits on the amount of certain items that although are set high enough not to affect me personally seems totally pointless!