If the server is going to crash or already crash, the market must be stopped !! and if it was down for most of the day, delay sales for 24 hours. if it was down for more than a day, the market must be delayed for 48 hours, and so on ...
i don't think it's a good decision to delay sales automatically. i guess the best decision is to pause them and give owners 24h to decide if they want to proceed with the sales or cancel them. the reason why i'm saying this is because many owners place their players on the market strategically, taking into consideration the deadline, since there are some days of the week which are much busier than others, thus there are days of the week when there is more chance of bidwars and getting higher prices...