Michigan Is this Intellistart quote too much?

I called my installer for a quote on adding Intellistart to my Series 5 Waterfurnace 4 ton and they quoted me $900. I had the unit installed in August of 2014 and surprisingly was talked out of adding it on at the time of order. It just seems to me that that is way high. Anybody know if that is accurate or not? Thanks.

 

I wasquoted $500 to add Intellistart to a similar model unit a few years ago.

 

I could have sworn that is what I was told when I first talked to them right after it was installed. But when I officially asked for a quote, they said $900. I'm going to have to call around I guess. Thank you.