Xbox One X is the most advanced console. the one recently released is Xbox One S Digital version. which has no disc drive and is purely digital and for streaming.
But Xbox One X is the most powerful of the consoles so far. if you have a 4K TV or monitor already, get the X if you care about 4K graphics. otherwise, the Xbox One S is fine for the casual gamer, and still produced great images.
especially if you think you'll get the next gen console next winter, you can start saving up for that one instead.
as far as pricing goes, you just need to search around all the sites. amazon, best buy, walmart, target, game stop, ebay, microsoft's on store, or others. and just compare prices, bundles, additions, special editions, etc.