1st post on here but I've been in the market for a 580 and came across this deal! Unsure of what the lowest price has been for this specific card but it appears to be the current lowest price for a 580 8GB in general.
The site says it last's for 15 hours, but I don't know when it started, sorry.
Umart adds a 1.5% fee if paying by Paypal, Zip or credit card (debit) bringing to total to $276.08 (shipping price included).
No fee if paying by Bpay or Direct Deposit - Price: $272 (Shipping price included