i see lot of replies are recommending spesh largely based on the scaling... yes, it did save a lot of butts this year (including mine) but if you really liked eco and are still in the midst of deciding i'd say it wouldn't hurt having a bit more variety in your vce studies.
vce economics, while shallow in depth compared to what you do in uni still allows you to gain some insight into how the world is functioning - i have a friend doing biomed next year who's never touching commerce-related subjects again, yet says she is glad she did eco for vce as it allowed her to understand some of the stuff going on in the news.
also, doing three maths subjects is something my school actually doesn't allow as they say it limits us too much, which I agree with entirely - you really don't need spesh for methods.