How much do i save by claiming 10 exemptions instead of 0 on 2000 a week?

uming you get away with it, you'll at least earn interest on the money you save. So, for example, if you can get 2% interest per year, and you're saving an extra $100 each week (all of which you have to pay back at tax time), you'll save about $50 in the first year, plus another $35 or so the next year, since you'll earn interest on the money you save (average saved balance in year one is $2500, and for the first four months of the next year you would earn interest on the full $5000). In other words, not worth it.