I don't think its possible to produce an oz per week in a 2.5 x 1.5 ft box. Thats only .33 of a square meter. Even if you could produce 500g per square meter (which is very high) every 14 weeks thats still only just over 10g's per week.
Just doing some simple math it's impossible no matter which way you look at it.
Maybe if you were very experienced and set up a genius vertical grow system you might have a chance.