Personally if your current wheels are not broken or worn and you are on a budget, I would reconsider replacing something that not broke. You didn't say how many miles you have on the rims, but money is money, you can either save that money for wheels later when they're worn out of if you bend one, or use the money for getting some odds and ends you need. This is one of those things only you can decide.
$500 budget does get you some very nice wheels, I'm not keen on the Campy suggestion because if you need a spoke you will have to wait for Campy to send it unless you have a large LBS in your area that sells Campy wheels. However there is wheel company that has rave reviews for making high quality wheels at decent prices called Hunt. The wheelset I'm going to show you weighs about 100 grams less per wheel than the Campy; they are also rated for a heavier rider of 286 pounds vs 224 for the Campy; so what's the big deal about the weight limits when you weigh less than either of the wheels? the big deal is one is only marginally better and will not last as long on rough roads as the other will, plus the Campy will require more frequent truing, and since you do not race, you ride on surface streets, and you like to go faster up hills this lighter Hunt wheel I think would be more suited for that, but you have to decide of course, You should google Hunt bike wheels and go to the road wheel section and look a the Superdura wheel road wheelset. Those wheels are right at your price limit, but sometimes you have to spend a bit more to get something a lot nicer, but the good thing is there is no shipping charges or taxes. Those wheels do come out of the UK so it will take a bit longer to get to you vs something sent within the USA of course.
Speaking of changes, when your current tires wear out consider getting a set of slightly lighter tires, but make sure you get them on a big sale with at least a 30% mark off because tires are way overpriced when you consider how much material is in a bike tire vs a car tire! Latex tubes is another option for losing some weight, but you have to be careful installing latex tube so as not to tear the tube with a tire lever or the bead of the tire. It's possible, depending on your current tires and tubes of course, you could save roughly 100 grams per wheel.
