Genuine Tasco scopes are good value, the quality of the chinky covers is a bit suspect but they do work ok, plenty good enough for a bit of plinking.
As you have an AA S410 I'd recomend you buy a good used scope.
i would agree with ratman2 it would be a shame to have such a nice gun as an s400 and put a cruddy scope on it it would be like putting a scoda badge on a bugatti varon