$ 1650 is the retail price the insert sells for here. Add sales tax, $675 for SS liner $450 for labor & 95 for permit.
Grand total $ 3009.50 complete. So, IMHO $1750 installed witha SS liner is an excelent price. Make sure you get the liner - all the way to the top of your chimney.
Or is that 1750 just for the labor & liner? Then I would say you are too high.