Only a single phase, one-year portion has the $500K maximum budget.  A multiple year, multiple phase, project budget can have a total that exceeds $500K.
So, yes, you can propose this but keep the following note in mind for the proposal preparation:
“Each phase of a multi-phase project proposal must have its own work plan, objectives and clearly defined deliverables to be evaluated as a stand-alone phase.  For example, there must be a high enough evaluation of the Phase 1 scope, deliverables, technical merit and team to get funded.  If funded, then performance of Phase 1 will be evaluated and determine if Phase 2 is also funded based on the success of Phase 1 and the work plan, objectives and clearly defined deliverables of Phase 2.”