This is what I think most people are missing. The upgrade is a complete component swap. What one currently has in her/his configuration is pretty much irrelevant.
Based on the price of the regular Sierra-1 woofer, I would think, that the new woofer would cost ~$150, $300/pair. As for the tweeter and cross-over ... the upgrade to RAAL 70-20XR from Nrt is $700. Upgrade from the regular tweeter to Nrt is $300. Theoretically speaking, the upgrade from regular tweeter to RAAL 70-20XR is $1000. The new, custom RAAL, is somewhere between Nrt and RAAL. Let's say Nrt to new tweeter upgrade would be in a range of a little bit more that 1/2 of RAAL 70-20XR. That gives us Nrt to new RAAL price upgrade to be ~$400.
Again, taking into the account the regular Sierra-1 tweeter upgrade to Nrt, the new tweeter upgrade would be in a range of $700 (including cross-over). That gives us the final upgrade price close to $1000.
Note: I forgot to factor in price of the regular tweeter. That would push the upgrade price to more of $1100 range.