Are lumber prices now high enough that building with brick/concrete is more price efficient in the US?
You'd never go with brick in seismic zones.  Concrete and rebar construction is way more expensive than wood.  Even if wood is up 200% concrete is 10x more than wood.  Cost is not the biggest factor.  Wood is easier to work with, requires less skilled labor, can be reconfigured later, and is a better insulator than brick/steel.  Material cost is a factor but not &quot;the&quot; factor.
I have heard people are switching to steel studs.  You might want to look at SIPs ( structurally insulated panels ) that have wood members 4' oc and use ~1/3 of the wood - still probably not going to be cheaper but will perform better.  Really unless your labor is free - people won't have had the time / experience to effectively make using a different material more cost effective ( except possibly steel studs ).
Really how you cost compare depends a lot on how you are going to have your house built.  If you are acting as the general then you'd get bids from people based on your plans.  If you want to compare cost in wood vs cost in steel, again it will depend on who you are getting to do the work.  Some subs will include material others will have the general order the material and the subs just do the labor.  In some cases you have a structural engineer who could do the plans with steel or wood.  The lumber yards then sometimes have their structural then do plans and take offs.  Steel I imagine would be similar.
Given the lower availability of people who work with anything but lumber I can't see a cost savings.