I hear you. I enjoyed the trial version so much but couldn't justify the cost of it just yet, even though I want it for "those occasions". I feel that the advanced version would be worth it if
(a) you need those advanced tools (well, duh)
(b) you have time to really learn those advanced tools and use them effectively
(c) you can justify the cost in terms of paying clients or true personal satisfaction as a hobby.
I couldn't yet see myself qualifying on that criteria, but for pure gear lust I know I want it and need it, hehe ;-)