hmm...how did you figure out it was a wrist pin? Those are actually pretty rare when they go out. I found this statement:
Piston slap/wrist pin noise is not usually detrimental. Will it shorten engine life? Oh, maybe from 200K to 175K. It'* mostly just damn annoying!
But then I've also read that in extreme cases the pin can come loose and score the cylinder wall. Chances are, however, that you're going to have to bore the engine when you do your rebuild. The price for an oversized piston is about the same so its not a big deal anyway but the clearances on a higher mileage engine would usually warrant putting oversized pistons and rings in to keep from burning oil 5,000miles after a fresh rebuild. That doesn't mean that the pin can't score your walls too much for boring. I'd suggest looking into this more and see what the damage possible is. You may just be able to drive it around to wherever you need to go without much worry of destroying your engine. It may be annoying and/or embarrasing but it'll give you more time to save and do whatever necessary before the rebuild. I searched for a long time for the best deal on a rebuild kit and my conclusion is that there just isn't a good deal out there for the series I. Best I came up with is going to a local shop and asking what they would do the work for. I glanced at the cost of the rebuild kit for mine and it was about $500 minus oil pump and gasket set so roughly $650 in all. Generally they'll tack on a little as a "finder fee" but charge the most during assembly. I'll be back later to explain more I gotta pick the wife up.