As of right now, there is no mention of price, but there is one bit of info out there. That being Resident Evil 4 will have the "Separate Ways" epilogue and Trophy/Achievement support. We can all assume that Code: Veronica will have Trophy/Achievement support, but that has not been fully confirmed.
Also, if you are interested in seeing the difference in visuals for RE4, below are a few comparison shots. I don't see the "upgrade" being worth yet another purchase, but at least it is a good option for those who had the foresight to hold out this long to actually play each game. Granted, the upgrades to Veronica could be worlds better, but I'm not seeing a good justification here just yet. Outside of the normal need to Trophy/Achievement whore. I'd still prefer a full HD collection to be released instead of one at a time in order to nickel and dime us.