The price of your item could drop for those reasons:
Basic commission— the bot items cost more than user ones in 7% (4% if you’ve got active Prime subscription);
Trade lock markup— Steam trade locked items have extra commission that varies according to the number of days left till the ban is over (from 0 to 13%);
Trade lock markup for the items which just left the trade lock— some items could’ve just left the trade lock. After that, they are already tradable but still have that extra commission of locked items for some time;
User items— you can trade or buy an item which was placed on our marketplace by other users with their custom price.