Hello, my name is George Bouris.
I have 20+ years of experience in software development and my main target is typography.
Your budget is limited for such a project, but we can start with a version that will provide all the basic functionality (shapes, text, font family, type, size, scale, xy positioning, color etc) and to provide more advanced functionality (transparency, rotation, effects etc) in a following version.
My initial proposal is for a windows based application. However, I'll attempt to write it in Xamarin with GTK#, to make the porting to Mac a lot easier. I can't promise, that it will work, though, because graphics is a low level functionality which may be unacceptably slow. In the latter case, I'll write it for windows only using native windows functions.
Regarding the application design, my intention is to arrange the various elements (images, shapes, text) in separate layers. So they can be controlled separately and in a future version various effects will be possible.
My written English is... as you see. My oral, though, is not that good, since I'm not a native English speaker.