What is an A-body 8 3/4 worth

I paid $450 for a complete 8 3/4 with sure grip 4.10s 15 years ago needing a going over. I just picked up a clean dependable 8 3/4 3.91s with super stock springs for $500. I probably wouldn't sell the worn it one for less than $500 just because of the crazy prices. Looks like I have 2, now I need another Dart!