Hi. I have been homeschooling my almost 8 yr old his whole life. I really wanted a curriculum to start, and yes, they get pricey. I used Calvert, as it seemed pretty all inclusive, and it has been. We have used the materials for K-1 for almost four years, as parts of it (writing, spelling and some social type studies) were not used right away, stretched out, etc. I liked having it all there for me, so I didn't have to create it. It has daily lesson plans if you like. I rarely used these, as we have not been as structured in our day. I figured the $700 or so I was spending worked out over time. (They do have a financial aid pgm, by the way).
That said, we have not been using it so much this year, as I have found more of our niche, found more websites and other resources. I also just re read the info on the state ed site about homeschooling, and your local school can allow you to use their text books. I am going to try that this next year, where I feel I need a text book. I have also found great used textbooks on freecycle. I am always looking, so tend to find things. Recently I have started using softschools.com for math fun, edhelper.com for lots of stuff (some is free, others require a $20/yr membership. National Geo, museums across the world, NASA, etc all have great kid friendly things as well.
Good luck! Hope to meet you at a park day soon.