Hi all, I'm an ATM newbie and want to make my first telescope. I'm looking at GSO 12" f/5 on agenaastro and a 317.5mm f/6 Protected Aluminum on Edmond Optics www.edmundoptics.com/f/precision-parabolic-mirrors/11895 and the prices are very far apart.
Is the difference just because of labor cost? What spec should I pay attention to to tell if one is better than the other?
Also from the wavelength I assume Protected Aluminum is the appropriate coating for telescope making?