You need to understand the basis of the whole FF/crop issue.
When cameras changed from film to digital, the folks then felt that they 'lost' something. Their existing lenses where 'castrated' to a 1.5x crop. They lacked lenses on the wide end because of this as well. Imagine if your widest lens was 28mm and now it was more like 42mm and not wide at all
They also lamented the increase of DOF, film better than digital (another long argument), viewfinder size, etc.
For a long time, sensor yields just could not justify FF digital cameras and thus FF digital became a sort of holy grail (passed into legend).
The new wide and ultra wide lenses have long addressed the issue of the loss of wide angle lenses.
The greatness of FF is exaggerated. It is just one of many possible film/sensor sizes. Why not MF, where you get to use a larger lens than 35mm?
How does it limit photography?
How many FF lenses you have?
Are they going to perform at the resolutions you want/need on a FF sensor (esp. edge sharpness)?
An A850 is at its price point because it has a performance at that price point (wrt FF cameras).