Nowaday, I seeing dozens of thousands of PDB files on the internet. I really want to determine a 3d structure of my interest protein myself. But I've heard that 3D structure determination is a complex expensive specialized procedure that can take months or years and hard to performed routinely or even purchased commercially. Could you please explain why and how hard it is? What is the requirements and how many budget is needed to perform this kind of experiment?

I seeing tens of thousands of PDB files on the internet. I really want to determine a 3D structure of my protein of interest. I've heard that 3D structure determination is a complex, expensive, and specialized procedure that can take months or years and is hard to perform routinely or even purchase commercially. 

Could you please explain why and how hard it is? What are the requirements and how big of a budget is typically needed to perform this kind of experiment?