Pronounced "too-fuh". Refering to the "two for one deal" in British supermarkets. It is used to add fluidity to everyday supermarket conversation (or any area that requires the act of purchasing) as the use of "two for one" has the tendency to slow down what would be a very quick sentence. As England is expensive supermarkets have introduced "two for one" deals, the population thrives on these deals in an attempt to keep the cost of their weekly shopping down.
"wait! buy these ones, they're on a toofah."
"it was on a toofah, had to buy it."
"man you got ripped off, i got those yesterday on a toofah"
"excuse me check out girl, do you have these on toofah?"