The $300 drum kit that you're referring to is the Ion Drum Kit, which can be found at
Drum Rocker. I'm definitely saving up for this bad boy, because it's a bad ass kit, and I really would like something more reliable for drumming. I believe it's already out, considering you can order it from their site. $300 is no joke, but as previously stated, considering it's also a real electronic drum kit, it makes it pretty worth it. However, if you're only getting the drum kit for the cymbals, just save your money for when they release the addon's for the typical drum kit. Not sure when those are getting released though.
As for the difficulty, ya I think everything got up'd a bit on the difficulty meter. I haven't checked vocals though since I live in an apartment and don't sing well when I think other people can hear me (I do great karaoke, but not rock band, and I have a loud voice, hehe). I'm still going through a solo tour on guitar, and definitely finding that it's more difficult than Rock Band 1.