They use the same glass, but that about it. The internals of the Meostar are why it is more expensive. The Meostar is 30mm tube and the Meopro is 1". The internal lenses are different and differ in numbers. The tube construction is also different. The windage and elevation turrets are also different. This is what I remember from a facebook message I got when I asked the same question. I'll see if I still have the message I got from facebook about the differences and copy and paste them here.
The Meostar is definetly the top dog in the Meopta lineup. The Meopro was designed to compete with the Zeiss Conquest.
The Meostar is comparable to the Zeiss Diavari and the Meopro is comparable to the Conquest.
I have 2 Meostars and they are sweet scopes. I have a 1.5-5 and a 4-12. They are heavy and about a half inch shorter in eye relief, but the optics are just as good as the Swarovski and Zeiss scopes for significantly less cash.