If you're planning a trip to Hawaii, you already know just how quickly costs can add up. Whether you've been stressing out over the price of your airline tickets or gasping at the price of a hotel, one thing that you don't need to worry about is finding fun, inexpensive activities for you and your family. No matter how long you plan to stay on Oahu, you'll love that there are low-cost things you can do to have fun. Don't skip the trip of a lifetime just because you're afraid that the activities are going to be costly. Instead, plan ahead in order to get the most out of your trip.1. Visit Germaine's Luau
Germaine's Luau is one of the mot exciting attractions on Oahu. You'll need to get tickets in advance, but they're all-inclusive and include your drinks, food, and the show. Unlike many luaus, Germaine's actually lets the audience watch the traditional ground-cooked boar being dug out of the sand before it is prepared and served for supper. You'll also love the audience-participation portion of the show. If you've always dreamed about being a hulu dancer, this is the show for you. Germaine's is located right on the beach, so you can even take a moonlit stroll by the water before you head home. 2. Take a drive to North Shore
If you rent a car during your trip, you have to take a drive up North Shore. This part of the island can't be beat. You'll drive along a scenic highway where you'll be able to explore tiny towns, stop at different beaches, and even get to see people surfing. Plan to take a day to drive up, stop for lunch, and enjoy a few hours of swimming. If you're lucky, you may even see sea turtles swimming in the waves with the surfers.3. Explore the Dole Plantation
Located in the heart of Oahu, the Dole Plantation is a must-see for kids of all ages. This plantation is free to visit, though additional activities, such as the hedge maze and train ride, have a small fee attached. You'll learn about the history of growing pineapples, get to see the pineapple fields, and have the opportunity to try everything from chocolate-covered macadamia nuts to pineapple-flavored ice cream. 4. Visit the Pearl City Mall
For a fun, relaxing afternoon, do some window shopping at the Pearl City Mall. This mall offers plenty for the whole family, including different stores, a movie theater, dining, and even Bubble Tea. Parking is free and there's plenty of space, which makes this the perfect rainy-day activity. You can even head across the street to one of the small diners for an inexpensive meal. 5. Check out Ko'Olina
Perhaps one of the most popular attractions on Oahu is the lagoon-style pools at Ko'Olina. This beach features several lagoons designed for the tourist who wants to relax at the beach without fighting the tide. The gentle waves make this beach ideal for anyone with small children or anyone who doesn't feel like surfing. While there are hotels at this beach, anyone is allowed to visit. You'll pay a nominal parking fee and be set for the day.