I can buy these blocks for 1.99 at a craft store. Fragrance oils are also an option. If you are going to use the fo's make sure that they are wax friendly. Some are not and they will not mix well with the wax. Ask who you are buying from to make sure, they are usually happy to help.
Dye alternitives There are as many ways to make candles as there are ideas.
One thing about using crayons is that they are colored with pigments that will clog the wick and will not allow your candle to burn. It is better if used as an over dip. If you use these methods don't expect your results to that of store bought candles.