A number of online retailers have gone live with Rock Band 4 listings that reveal the release date, the price, and the Band-in-a-Box bundle.
Rock Band 4 was never given a solid release date outside of "fall 2015." According to Amazon though, the game will be out October 6.
The edition shown in the link above is called the Band-in-a-Box Software Bundle. It comes with a copy of the game, the guitar, drum kit, and a microphone. Buying from Amazon will net you 4 extra tracks.
This edition is priced $250 and is available for both PlayStation 4 and Xbox One.
The other, more affordable bundle, comes with a copy of the game and just the guitar, and will run you $130.
Interestingly, Guitar Hero Live's price is $100 for the game and the guitar controller, which is $30 cheaper than Rock Band 4's similar edition.
There's a good chance Harmonix will be on stage at Microsoft's E3 presser in about 30 minutes to reveal the release date and maybe show the drum kit.