Vauxhall Vectra B. 1.8ltr. petrol - leaking fuel tank - paulv1

i noticed a strong smell of petrol at the rear of the car, took car to my local garage

he thought it maybe the breather pipe, but no such luck it's the actual fuel tank that is leaking, he reckons a new one from vauxhall is between £200 + £300, he advised me to try and find a second hand one, which i've done it's a used one with 1 months warranty as i'm currently unemployed this is really my only option, with p + p, vat it totals £48.00 but it depends on how much labour he's going to charge me? are second hand tanks ok to use?