Should I rent or buy?

If you are a beginner I recommend renting.  Once you have determined you like playing and are making progress you can purchase if you want.  Most music stores have a rent to own option.  Often the instruments music stores rent are high quality instruments.  Be wary of flutes that are very inexpensive.  Often these flutes are made by "no name" companies with non-uniform parts that are difficult if not impossible to replace or repair.