1. There are always some buying orders exist because the projects staying behind bounty stakes are good (thoroughly selected).
2. if you sell stakes and set too high ASK price then probably buyers will not be willing to purchase for your price.
Consequently, if you set a lower price than other stakes sellers (that's 0.000025 ETH/per 1 stake in the example above) then your order will be matched faster.
But if you want to sell your stakes as fast as possible then you shall agree with the highest BID price currently available (that's 0.000024 ETH/per 1 stake in the example above)