DigiDesign Structure? Worth it to buy used?

[musicallife]

I wanted to know if I don't know how to use pro tools yet, and currently have 7.4/7.3 authorization, am thinking of upgrading or possibly selling, is it a good idea to buy
used Digidesign Structure for $100 (also with, thrown in, 2 Steinberg Internal Mixing DVD's (Internal Mixing Tutorial :: Steinberg Media Technologies GmbH :: www.steinberg.net )
I know I might sell my m-powered and if I switched to pro tools LE but Structure can work in LE or m-powered (I know there is one optimized for M-powered too)
and also this older version of Structure seems to come with 15GB of samples whereas the new one seems to come with 19GB of samples, and it comes with trial of Goliath but the trial is up and the license for that costs like 400 dollars new, and did not see it being sold used-
Basically has anyone been using this Structure plug in and do you think it's good for a beginning recording artist to have on hand?
I have Sonik Synth 2, but it seems structure is much better?

thanks,
Jeremy