The money its going to cost you will more or less outweigh the cost of a DSMlink. The crank itself is going to cost you. Finding one in good condition for starters & then having it nitrided is about $150-$200, depending on who does it.

Jerry has spare ones that he sells for $350 I think. If your only options right now are to rebuild a 7bolt or buy dsmlink, the cheaper route is going to be buying the link.