So I'm a complete new guy when it comes to the technical aspects of cyclocross bikes and had a question I couldn't find the answer to using the search function and Google. Is there a big difference in quality/durability between cyclocross bikes that cost $3000 and bikes that cost $800, disregarding the weight of the bike? I really want a solid durable bike that I'd use specifically for road cycling, if that's possible, because I'm on the larger side of cyclists and really put the wear and tear on my previous bikes. I want to start cycling again, the ideal bike I'd like for general-purpose riding is a cyclocross, and budget hopefully on the lower end of $1200-$800. Thanks for any info or suggestions.
Also, I've been slowly getting more and more into the Shimano vs. Campagnolo debate issue, is there a big price difference between the two, or is it mostly a matter or preference; I'd assume the Italian Campagnolo would be more expensive than a Shimano but cyclocross is completely new to me.