When award will be based on the best value tradeoff source selection process, which permits tradeoffs among price and non-price factors, the Government will give a price evaluation preference to historic properties as follows:
(a) First to suitable historic properties within historic districts, a 10 percent price preference.
(b) If no suitable historic property within an historic district is offered or remains in the competition, the Government will give a 2.5 percent price preference to suitable non-historic developed or undeveloped sites within historic districts.
(c) If no suitable non-historic developed or undeveloped site within an historic district is offered or remains in the competition, the Government will give a 10 percent price preference to suitable historic properties outside of historic districts.
(d) Finally, if no suitable historic property outside of historic districts is offered, no historic price preference will be given to any property offered.