Classic Records Zep series ?

Classics' site isn't working for me, but it appears in poking around that the first 4 Zep re-issues are available in both 180 and 200g vinyl -- with the expected price differentials.

Is this correct, and is this just working the: 1) re-issue market, and: 2) the heavier-is-better angle? Kinda like that stuped 89 octane gasoline?