When you're meeting with wedding photographers ask them if an engagement portrait session is included or if you can add one. You want to know the added cost, if there is one, for the shoot and the cost of prints or albums from the shoot. Find out how you will receive them, as printed proofs, on a CD or if they'll be posted on a website to review.
Besides framing a few photos in your home, and maybe gifting one to your parents and his, you can use your engagement photos on your save-the-date cards, wedding website and holiday cards, if you send them.
Engagement portraits are not a wedding must-have, but how many times in your life will you hire a professional photographer to take pictures of the two of you? It might be worth cutting other areas of your wedding budget to make room for this expense.