It's REALLY easy to make your own hydrometer. Depending on how sophisticated you want to make it, it can cost you anywhere from $0 to ... It can even cost you more to make it than to buy it but in that case you wouldn't have the satisfaction of making it yourself. Go figure.
My hydrometer is...
I am currently in the process of making 2 wines. The first batch is an Orange and Banana (very delicious!) and the other is a Grapefruit and Banana (I only made this last one because I felt like experimenting). As for sugar, I used a blend of table sugar, dark brown sugar, and maple syrup...