Sulcalibur

Designer Beta worked fine but every time I download and install Photo I get an error when opening it demanding I delete the app as it will damage my Mac.

I love a deal as much as the next guy but serious, for $50 this app is a steal. If you are after something cheaper maybe try out Pixelmator. It's nowhere near as powerful and has very basic vector tool, but it might fill the gap between basic editing and price.