There is a PM picture, up on the 2nd link, kind of hard to see so I can see how you missed it, and there's like 4 skype messages in the third link? I do not understand.
Scammer's profile link: http://www.sythe.org/members/439950-drunk.html
Explanation of the trade: 20$ for an RS3 account
How they scammed: He said he will give me 20$ in exchange for the account, in the end he just stalled about me lieing there's 30M on the account and scammed me for the money...
Given that the exchange rate of gold to gems is 100 gems for 13 gold, and that 800 gems equals to 10 USD I am asking around 20 USD which is approx 205~ GW2 gold. (Which is not that much really, 2 days of silverwaste farming)