First off, I think JerryFish (Reply #91) did an excellent job studying the MSRP cost difference between the 1Ds/1DX and the 5D series, for the last 3 generations. That Table is very informative and telling. See below.
I would make the following points, regarding the rumored MSRP:
1. Keep in mind that through the upgrades of each of its models (including FF series), Canon has done its best to improve various shortcomings of the previous generation. Even though upgrades do cost money and expense, note that such improvements (whether the Pixel Count, ISO, IQ, AF, Processor, FPS, etc.) did NOT result in overly noticeable MSRP increases. (by the way, that is almost true amongst other manufacturers as well, including Nikon). By improving the previous model’s features, and maintaining (or dropping) the MSRP for the newer model, Canon has done very well in holding or improving its position in the market share.
If were talking exclusively about the 5D line then Canon has not really delt with these "shortcomings" before, the 5D mk2 offered a superior sensor and video over the Mk1 but did not offer a significant improvement in FPS, AF or viewfinder coverage. This new 5D is offering specs that are far closer to the tradisional 1D/1DS market.
3. In its head-to-head competition with Nikon’s D800, Canon cannot reasonably ask for a higher MSRP than D800’s $3,000. That is the not-to-exceed price ceiling. In fact, with D800’s long list of expanded features (36MP, Advanced AF, 16-bit Image Processing & Excellent IQ and Video, Built-In Pop-Up Flash, Automated HDR Mode, In-Camera Audio Monitoring & Headphone Jack, Active D-Lighting, USB 3.0 Connector, etc.), it would be wise for Canon to price its new 5D iii/X conservatively at a lower MSRP than D800’s $3,000. An MSRP of around $2,700, similar to 5D II (upon its introduction) would be reasonable.
Based on the above points, if Canon wishes to enjoy the same success and popularity that it had for its 5D line through the past generations, it should price its new 5D III/X at around $2,700. Otherwise, D800 will win this battle. Simple as that!
In fact, the more I think about the [CR3] report for a MSRP of “Around” $3,500, the more it seems to me that perhaps that price is for a KIT Package, which includes the EF 24-105/f4 L IS II lens. Now, That would make sense
It would definately be more sucessful at a lower price however it seems likey(although neither were mention on the CR3) that this new Canon will offer superior ISO, FPS and posisble AF performance compaired to the D800.
As has been mentioned MRSP isnt street price, tradisionally even brand new products are often avalable for significantly below that level. Nikon seem to have bucked that trend by enforcing the MRSP which has likely resulted in it being significantly lower than it otherwise would have been.