Not as cheap as I thought I guess. I paid $80 for mine loose and the guy that sold him to me got offered $150 for it after I bought it.
I just found this one on Ebay with the box. Not as good condition as yours and doesn't have the sticker sheet but it's $50 less:
http://cgi.ebay.com/Transformers-198...#ht_1514wt_913