Believe me, teachers KNOW that things are tight. Our supply budget has been cut, which really means that we're now buying more out of our own pockets.
I have several comments on keeping project costs down:
Choose wisely. When my kids bring home anything more than the simplest project, they always seem to have choices. Some of these are more expensive than others, and as a parent I absolutely have the right to veto a certain choice and tell my kid that she can't choose #4 on the list for whatever reason. So tell your kid that he ought to make the power point (free) rather than the diorama that'll require a $20 set of plastic African animals and a yard of animal-stripe fabric. Tell him he should write a poem (free) instead of baking a cake. Suggest that he make something out of paper mache (is there anything cheaper than newspaper, flour, and water?) rather than a project that'll need pricey balsa wood. Limiting his choices won't hurt him.
Put the kids in charge. If your kids balk at having their choices limited, put them on a budget. Tell them that over the course of the school year you will spend X amount on projects . . . and keep a running total on a paper inside a kitchen cabinet. Tell them that they can have whatever's left at the end of the year. I predict the less expensive options will become much more attractive! Or, if you think your kids are too young to manage a year-long budget, put a $5 limit on each project.
Be more creative. So much stuff is available, and we've become lazy because of it -- we think of buying as a first choice rather than thinking about what we have laying about the house. Instead of buying a tri-fold board for a poster, use the top of a copy paper box and make it more of a shadow-box. Instead of buying expensive die-cut letters, cut out your own. Instead of using expensive computer printing, print out "border letters" and color them in with crayons. I always made great projects when I was in school, and I don't remember my mom ever buying me much of anything. For example, I remember once doing a history project on fire -- I found an empty #10 can in my mom's pantry, and I attached paper all around the sides showing advances: open fire, candles, stoves. And inside I had flint and steel, with which I showed the class how to start a fire without matches. I remember writing a comic book called "Captain White Blood Cell" for a science project, and I was the ONLY student who received an A. Recently one of my own kids needed construction paper with which to cut out letters -- and we didn't have it in the house. So we looked around and found a couple Lands' End-type catalogs . . . she cut out letters from the brightly colored clothing, and they looked great. Need to make a scrapbook? Instead of buying one and inserting expensive paper, sew together a homemade book with a cover made from cereal box cardboard covered with fabric from a worn-out shirt. Kids will be more creative and resourceful IF they aren't offered store-bought supplies.
Don't feel that every project has to be a showstopper. Trust me, the majority of the students aren't knocking themselves out over projects -- it's really the top 25% who go all out consistantly. Projects should be graded on the quality of the thought process that went into them -- not the quality of the scrapbook paper that was used to create them. Creative always tops expensive.
Recycle. Why would you ever need to buy multiple tri-fold boards? Recover the old tri-fold board with wrapping paper or brown paper bags. Or cover the board with that half-can of spray paint that's already in your garage -- don't worry about your child not having a color choice. When my students turn in projects, I always give them the choice to take their tri-folds home or leave them -- and I give them to next semester's students who ask. My own kids have a never-ending supply of the super-thick plastic signs: My husband's company prints up expensive signs for conferences (they can't be re-used because of names and dates), and he brings them home for the kids' projects. He does insist that they "use" the side with the company side so that no one sees business information. Once a year I get a whole bunch of boxes at school. They happen to come with two pieces of small poster-sized thin cardboard in every box . . . I keep it all. Some goes to my own classroom, some goes home for my own kids. Similarly, one year I saw one of the coaches throwing away three cases of two-year old sports-schedule posters, which at some point had been offered to students. I took all three cases and used them in my classroom: They were good poster board, although they were printed on one side -- I had them for about two years, and I'm sad that I've used them all up.
What do you have sitting around that could become project fodder? Oatmeal cans? Shoe boxes? Styrofoam meat trays?