To be fair you did not specify you were looking for a shipped price. If you're shipping an entire PS (transformers and everything) along with the harness then yea, $75 including shipping seems about right.
Sounds like you did pretty well. I had two of these listed for sale for a while. One I ended up selling for the cost of shipping. The other I ended up getting $40 for on ebay (plus shipping). Both within the last 6 mo or so.