I would very much like to see a few more tiers of the super supporter achievement. 

Since there are a fair few people here who spend good money on credits it would be nice to be rewarded with a little exp boost or some cash for our continued purchases from the site.

perhaps something like this :

$1 spent = Achievement : 1 credit

$50 spent = Achievement : 5 credits, little exp boost

$100 spent = Achievement : 10 credits, medium exp boost, £250,000

What do you think?

amend it for credits bought on the ingame marketplace and its got my support otherwise its a pay to play achievement

TTD, that would kinda defeat the purpose.

That said, I don't like this idea for the reason ttd just described. I'd be interested in seeing a reward for the major financial contributors to the game, but i'm not sure how i would like to see it

why not a "credit collector" achievement?

I'd be ok with a credit collector achieve. But i wouldn't pay credits for it.

I think that the "reward the people who pay for this game to exist" concept and the "achievement based on collection and/or use of credits" ideas should be seperated

they do currently have a investment idea in place which i think is better than an achievement

very true