WRT prices, you'll need to say a bit more about what you're looking for. With both companies, prices vary with the size of the range, as well as the features. This or that back; all burners, a griddle or a grill, a french top (available with BS) -- all of these change the price. BlueStar are all gas; Wolf offers both gas and dual fuel ranges, with electric ovens, and the dual fuel ranges have different (higher) prices. For BlueStar, their top line -- RNB -- ranges start at just about 4k for 30" and about 5k for 36". Last I looked at Wolf - maybe a year ago -- prices were similar, if maybe a bit higher, at 30", and there seemed to be a bit more of a spread in some of the larger sizes. BlueStar does offer a less powerful line of ranges -- the RCS models -- that still have ample output for the vast majority of cooking needs and are priced well under both BS's RNB line and all of the Wolf ranges. If these have the features you want, you might find very good value for money in the RCS.

Overall, prices might tend to be slightly lower with the BS RNB than Wolf, and a good deal lower with the BS RCS if there's one configured as you like. OTOH, maybe the best value for money is getting the thing you really want, provided it's in budget. Also, with Wolf, there might be more of a chance at finding a deal on a floor model or what have you, just because, with wider distribution, there are so many more sitting on dealer floors from season to season.

The BS RNBs are available all stainless, or with a body in your choice of 190 colors at no up-charge.

As to what you might want: you haven't said much about your preferences or why you want to sell your Aga range. What don't you like about the current range that you'd like to change? Both Wolf and BlueStar are very well regarded products. Wolf probably has greater distribution and name recognition generally. And Wolf does very well in customer satisfaction surveys (which often neglect smaller brands, such as BlueStar and Capital, entirely). BlueStar ranges are all gas, all open burners -- direct flame from exposed burners, as in restaurant ranges, surrounded by cast iron bowls and covered by cast iron grates. The RNB line offers a very high powered burner -- 22K BTU -- as well as intermediate and simmer burners. For most cooking -- the large majority of techniques -- nobody needs that output, but for certain techniques it's really helpful (and for getting a large pot of water to a boil quickly, as well -- and for my own idiosyncratic preferences, for having it come back to a boil promptly once I've added pasta, etc.)

Wolf offer sealed burners (at 36" and up, they also offer something they call and open burner that's sort of in-between). Some folks really like sealed, as there's a neat smooth top running across the range top, under the grates. Others (me included) find open easier to keep clean, as the grates get a quick wipe and as easy to clean stainless trays catch anything that falls through. Open burners offer more direct flame and are more efficient, although the relative efficiency of the burners may not be important to you. I think that top output on Wolf is 18K btu on 36" and larger models, but maybe only 15 in the 30" ranges. There's nothing wrong with 15K for the large majority of techniques, and yes you can bring a large pot to a rolling boil on a 15K btu burner. OTOH, if you're doing Wok cooking, or Wok-like western techniques that involve a quick sear, you'll really notice the difference with higher output. And for boiling water (or anything), 22K btu is noticeably faster than 15. Wolf ovens generally are well regarded. I like my large BS oven, and BS comes with a terrific broiler.

I bought the BS because I was crazy about the burners and I'm very happy with my choice. The burners have delivered, as I'd hoped, and then some, the range looks great, and the broiler has been a very nice surprise (wasn't really on my radar screen much when shopping, but it's been well appreciated in use).

OTOH, you'll also find many happy Wolf owners.