A week for $200, including taxes, is usually a relatively good price. Do you need to use Avis or can you try others? Cheaper cars I found in a 3 min search (Kayak for these listed below):
-Advantage at LGA. $183 for an economy.
-Hertz at ALB. $100 for an intermediate.
-Avis at ALB. $144 for an intermediate.
-Hertz Poughkeepsie. $164 for an economy.
My only other suggestion would be to use AutoSlash, as I can't come close to $200 with any public codes.