No. $2 + GST is not enough a deterrent to many.
One forum where 'trust', 'honour' and 'fairness' is upheld to the max is a US forum I sometimes do USD 3 figure or more transactions.
There, the classifieds are ruled with an iron fist - that is to say, your word is your honour, and any infringement gets you a chance to make amends and publically apologise, or face life-long banishment besides federal action. I've seen guys in Europe posting up asking for help because some chao nang in the US shat them on a deal, and within a month or so, so much 'heat' was put on the scammer, both internet as well as forum members e-mailing both the seller and calling/e-mailing non-stop to the local police/FBI dept (in the US, internet fraud is a federal offense) and offering to 'drive by and pay a visit' to the chao seller so much so that refunds in full were made.
Think that's going to happen here? Notice, our word and reputation is of so little worth that even the i-trader listing is of literally no use. No one bothers to update it, and no one bothers to ask for updates after a transaction simply because no one here, for the most part, honours a word spoken as a promise.
CS classifieds needs an effective and strictly enforced value system for it to be taken seriously, to avoid or minimise just about every sort of unfair and unetical trade whis is so openly rampant that no one notices anyomre, and for words like 'honour' and 'trust' to be taken seriously.
As a wise man once said, (you can't ever fault him for logic and insight, can you?), unfortunately, ours is a society that only understands two things: punishment and reward.
A $2 or even $5 per classified thread ruling would be insignificant, in light of the big $$$ to be made by indiscriminate trade in the photo industry. And any sum larger would bring on a mass outcry.
This is one area, that, if the mods and admin take on an iron fist, would truly benefit photographers in the long run. But of course, it's very hard work to moderate the classifieds, and probably harder work for people to act ethically and honourably. Such, is our people, only IF they are allowed to be such.