Class III vs. Class II medical

I am going to take my medical on Tuesday. The price
for a Class II is the same for a Class III license. If I don't
renew my Class II within 6 month sor 12 months (?) it goes down
to a Class III. I don't plan on exercising the Class II but who knows,
maybe I'll get my Commerciial and CFI in the next year. I don't have
any plans for now but who knows. Actually I don't even think you
need a Class II to act as a CFI.

Any reason I should get a Class II or should not get a class III?
to me it sounds like get a Class II and at worst, it cost me an
extra 15 minutes.

Gerald Sylvester