May 20, 2018, 4:32 p.m.
Here again latest cancelled order from the same buyer: 155078
What apparently happens is that the gift is taken down and the credit is subtracted from the buyer. Shortly after that something happens and the order is cancelled. The buyer gets his credit back, but the gift is taken off from market. If he tries to purchase again, the same thing will happen and another gift will be taken off the market. The purchased gifts are taken off the market and for them new market orders need to be created.
This happens quite a lot, see one of the recent examples: https://dispenser.tf/market/16720/
Last sold item supposedly for 8 keys and Volume is 1, means it happened very recently. But if you check done deals, there is no filled order that was sold for 8 keys, last item sold was in january and it was for 3 keys. This is typical sign that the 8 keys order was cancelled and the seller needed to recreate new market order.
I hope you can go through the code that handles market order purchases and spot the problematic part, it definitely affects gifts and credit orders, none of these are crypto orders.
*bump*
Same problem is still going on, here some new cancelled orders from today: 155048, 155055.
Any reply on this subject would be appreciated, thanks.
I am not sure about the cause. The system does check credit during purchase. This error should only apply to crypto trades as the price of crypto may change and buyers could be out of balance but should not apply to key purchase.