Will we save money by having our reception outdoors or does that end up costing more?

You may save some money going outdoors, depending again on what you want. There are many rental companies who specialize in weddings and should have everything you need. We've been to some very lovely outdoor wedding/receptions. Outdoor considerations include: Back up tents or other cover are a good idea, in case of rain or blazing sun that will melt not only your cake, but also your guests. Tents should be set up several days prior to the event to ensure dry ground underneath. Have an adequate number of tables/chairs for both the wedding and reception. If the reception will go into the evening, you will want lights and perhaps heaters, depending on weather, which also necessitates electricity (and perhaps portable generators). If insects are a problem in your area, consider pre-spraying with insecticide or lighting punk sticks or citronella candles. If you want dancing, you may want to rent a portable dance floor. Also remember to consider the needs of any of your guests who may have special handicap or accessibility needs. Parking and rest room facilities should also be adequate for the number of guests you are planning. Then you have to consider the food/catering and preservation of food due to weather conditions. And probably hiring a bartender & purchasing liquor. Parks may require special permits for large events (and may restrict alcohol use) and/or security personnel. If you have it in a park (or actually anywhere outside), also plan for cleanup duty by someone after the affair. Check on the trash disposal requirements of the park. Some people have had pot luck beach parties or backyard barbecues for receptions, which can save lots of money. It just depends on your choices. EZWeddingPlanner advice section has more reception site details and suggestions.