Contract values goes up after taking into account a lot of factors, such as how many NRL games his age, injury liability, suspension history, health, kicking average and representative history etc etc.
However, the final figure is what club thinks his value is to them, and what he brings to the club.
The average NRL contract is around 350k but Adam is a good goal kicker, i a utility player, has a great 5th tackle high long ball, and has Represented Lebanon. These are just some of his attributes.
Based on just these attributes, he is worth 500k to our side imo.
I think 350k is insulting considering the cap always increases.