Whaleshares is not a purely traded token... We have only released whaleshares as prizes for contests, giveaways on our discord server and to reward people who have done things to benefit our community and steemit in general. The tokens on the bitshares exchange are ones that people won and decided to sell for BTS. It makes sense that they would cost more that way than what you get for post payouts since if they were less the people would just use them to upvote their posts. There is also a very wide range between the bid price and the ask price so if you just took the sell price you probably could have gotten them cheaper. We have been slowing down on the contests since HF19 so as to regulate the supply so the voting power doesn't get drained too much but we will be starting contests again soon with prizes adjusted for the HF19. We have pretty much decided that we will probably not be offering whaleshares officially for trade but instead will keep them purely for contest prizes and rewards for people benefiting the communities.