The short answer is — it depends. What are you looking for?
Storm doors range in price from as little as $100 all the way up to $1,500+ for the more custom sized and style security-type doors. On the average, though, you can expect to spend about $200-$400 for a good quality storm door from a retailer like Lowe’s or Home Depot. Installation is around $125-$200 depending on what other work needs to be done (firring, one way screw removal, disposal fess, etc.)
Now, let me say a bit about the cheap storm doors. You’d be surprised at headaches you will avoid by spending an extra $25-$50. CHEAPEST PRICE DOES NOT MEAN THE BEST VALUE STORM DOOR. With the cheaper storm doors, you will have problems with getting a good seal at the bottom of the door, not to mention a good seal around the door as the manufacturers’ skimp on the weatherstripping as the price goes down. Also, you may notice fewer hinges, which means the door will sag more over time and frustrate you to no end.
The more average to more expensive doors will let you pick hardware colors. One important difference is most top end doors come with two door closers instead of one. They are mounted at the top and bottom of the door instead of just at the top. This gives it better rigidity and slower closing speed. Remember, buying a separate piston is only about $5.00, so don’t spend an extra $100 on a door just to get a second closer.
The best way to get a sense of pricing to search online. Personally, I shop online to compare prices and narrow down more what I am looking for. Also, some are Energystar compliant which means they may qualify for an IRS tax credit.