Hello John!
In this economy, I would say your budget has a big vote! I have stayed at Port Orleans Riverside (POR) in the past and it is a very lovely, relaxing resort. There is also the the added convenience of taking a boat ride to Downtown Disney (although that in itself may end up blowing your budget!).
Honestly, if you can swing it budget-wise, I would go for the Beach Club (BC). I'm also from a family of 5 and, like us, I think you will enjoy the queen beds and day bed in the BC vs. the double beds and a pull out trundle bed at POR. You can't beat the pool area at BC and all the fun things to do and restaurants to visit on the Boardwalk. You are also within walking distance to two parks - Epcot and Hollywood Studios (you also have an option of taking a leisurely boat ride to these parks).
I'd like to recommend a couple websites were you can keep an eye on discounts. My absolute favorite is
Mousesavers.com. If there is a discount available for anything Disney - it will be posted here! I'd highly recommend signing up for the newsletter so that you are alerted of special deals.
Disney has also been very good about
posting special offers here. What I find helpful on the Disney website is you can go through the booking process without actually submitting to get an idea on prices, etc.
I hope this helps with your decision. Diane :)