The release of the Apple iPhone 3G on prepay on September 16 has put box breakers on red alert.
But despite the slumping pound, the UK prepay price will lead box breakers to source stock from abroad.
The device launches on prepay at £349.99 (8GB) and £399.99 (16GB). Many box breakers were expecting a lower price and are establishing contacts overseas.
One breaker, who claims to have unlocked more than 5,000 iPhones, said: "It will be a massive target for box breakers. I have a list of nearly 100 people worldwide who have asked me to get one, and I expect that to grow."
Another said: "I have set up contacts abroad to get cheaper stock. Around 20 dealers are interested, and I expect that to increase."