I agree, we don’t necessarily have a reason to expect people will use BKS as a trading token like we do NSR; it could be considered as primarily voting tokens and open market trading is not encouraged like it is with NSR. Also, BKC would be primarily a consumable resource for the exchange, so open market trading of that is somewhat discouraged as well when compared with NBT. Therefore, B&C can afford to have much higher fees than Nu.
In terms of auctions, if B&C wants to do a share buyback it can do so in big events rather than the continuous burn gateways of Nu. That way, the volume is high and Tx fees won’t become a burden.
So, how much friction do we want to impose upon BKS Txs? As the chunking creates fixed-size outputs, we can estimate the blockchain size/BKS, and thus the % cost. If 1 input costs 200 B, there are ~5 inputs per 1 KB. So, the fee gets charged once every 5 BKS. A 0.01 fee translates into ~0.2% fee.
This calculation for Nu:
10,000 NSR/input
fee gets charged once every 50,000 NSR
If fee is 1 NSR, Cost = 0.002%