Why has my item price dropped after the trade?

The price of your item could drop for those reasons:

• Basic commission — the bot items cost more than user ones in 7%;
• 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.