I agree with Daytona. I owned and operated an antique store for many years. It's about what it's worth to YOU. I found by a VERY strange coincidence a book once owned and signed by my grandfather on Ebay. It sold for about ten bucks, but I would have paid hundreds for it as I only have a few things from him. See what I mean. If you are buying it for resale, then maybe $150 is too much. If it was for my car, I'd pay $150.00. Heck, a year specific original factory service manual is about $75.00. So I think $150.00 is quite reasonable. Go for it!!
Matt B.