The Tier System has to suggest the possible Tier of the Build. A Caster with one Tier X spell would be a Tier X build; multiple Tier "X+1" spell would also be a Tier X build. However, the Tier is also based upon ECL. What is Tier 1 for ECL 2 is different from ECL 4 and ECL 6. What is Tier 1 for ECL 18 is Tier 1 for any ECL that it could be cast.

The project would be too large without a full community to help.

How do the meta-magic affects the Tier of spells?
What spell level do we could the spells with meta-magic applied to them?