The kind of mount you would need to carry a 10" newt effectively becomes very expensive.
Whilst a 10" newt is nice for visual work, you really dont NEED that much aperture to do good astrophotography. Check out what many acheive with just an 80mm refractor.
Inside that budget you could maybe get a 10' dob for visual AND a smaller scope on say a motorised heq5 for your photography needs.