Hundreds of details account for the variance in BC pricing. Some are worthwhile, such as the quality of the material, how rugged the connection of the corregated hose is, or the stitching. Others are largely cosmetic - colored panels, padding, D-rings, etc. In terms of function, they all more or less work the same. Your largest issue is how they happen to fit your particular body type, so that they are comfortable and easy for you to use in the water. Don't buy one because its comfortable on land. You won't be using it on land. Dive many, compare & contrast, before you lay out big bucks for one.
In terms of type, you have no real worries. If you plan to basically conduct recreational dives within NDLs, etc. get a BC. They're quick, comfortable, and all your buddies will have one. If you plan on getting into mixed gas diving on a regular basis, where you are consistently conducting planned decompression dives, get a backplate and wing. They're quick, comfortable, (easier to use with doubles), and all your buddies will have one. Which manufacturer in each category is strictly a matter of personal preference. Pick the one that works for you best. They all work pretty much the same, there are some variances in the details (see above, re: trying many of them out before you buy one.)
There are literally hundreds of threads on this topic on ScubaBoard. Use the search function with the names of some products you are considering, and review the pros and cons hotly contested previously. As you might imagine, you're not the first guy who had this question.
Good luck.