You can easily find a bunch of S13 240sx's at any junkyard- just find a U-Pull-It and call for the price first- should be $20 or if it's more just hide it somewhere in the junkyard and go back on "half price" Wednesday and purchase it then.
I used to pull them and put them on Ebay- which would be my first or second choice for you- they go for $50. The part itself is foolproof- no need to get a brand new one.