cool idea! I will retire three chars and come back in two years and whack your asses in plate and flamberge!
seriously, why do you think its harsh and need to be balanced out? Yeah sure, if you only play casual you won't have the money very fast to use high tier equipment. But for every playstyle and built there is, you can choose an adequate equipment set so you won't lose money (but earn some) and should get along very fine. And like every other player after some good rounds you can even consider buying/using some better equip. what do you want more?
btw, how does a "casual player" retire these days anyway? (with bonus of course) For my sensation I played very hardcore since the patch came out and i'm still nowhere near lvl 31. What I call a casual player would take months to get to lvl 31. And if you get there you shouldn't have money problems so this idea is really screwed, sorry.