I have to say DD1 has about 7/8 uniforms (inc skirts, trousers and pinafores)... and the same amount of polo's and then has 3 school sweaters. DS has 3 pairs of trousers, 6 polo's (but 3 are still new in their packet) and 3 jumpers...
DD1 will go throguh a full uniform almost every day for nursery purely from being a filthy little monkey and getting paint/playdoh/sand etc all over herself... She's just so messy that i could never send her in the same uniform two days in a row...
DS on the other hand could quite easily wear the same uniform all week and it would look as clean at friday hometime as it did on monday morning... He's very clean, hates mess and is brilliant. We change his unifrom once a week normally so he'll have 2 uniforms and a spare and some spare polo's.