Here's my take on belts and buckles for what it's worth. The nicest buckles are either sterling silver or gold. You can purchase a nice sterling silver buckle for something on the order of $150 or so. Solid gold will, of course, cost many times that. A thick gold plating on a base metal or over sterling (giving you vermeil) would be pretty nice too. If these are too expensive (and they are for most of us), nicely-finished silver- or gold-tone will do.
I get all my belts one size too large. I then go to my cobbler and have him cut them down to exactly the right length to allow me to use the middle hole to fasten it. I have him put two snap closures on it, allowing the two leather keepers to be at the right locations, rather than stitching it after resizing. The whole process costs me about $15. This allows me to use one really nice silver-finished buckle and one really nice gold-finished buckle with all my belts (of a particular width), to allow me to match metals to my other jewelry, shoe buckles (on monk shoes), watch case, etc., and to have just the right belt color for my shoes. I have dress belts in widths of 1 1/8", 1 3/16" (30 mm.), and 1 1/4" and thus have high-end buckles in both silver and gold in each of those widths. I don't go any wider than 1 1/4" with dress belts, as they'd look a little off for my height (6 feet even). When purchasing belts, this allows me to concentrate entirely on the strap and not worry about the buckle (or purchasing just the strap, as is possible from some sellers) when trying to get good color and texture matches for my shoes and outfits.