I do not think you can buy a ship the character cannot use. Myself as an example, I can use Tier 2 ships, but I could not purchase the Tier 3 Cruiser from the C-Store.
Maybe at level 45 it is moot.
You're right - I was, in my previous (and now edited) post thinking of what occurs when you are using an alt; namely the ships that you purchased with your main toon show as available to your 'second' toon, but are 'locked' until you reach the required level.
Personal T6 Ship Wishlist:
Nova/Rhode Island class with Hybrid Pilot BOFF seat.
That is all. (guess this wasn't really a 'list' after all!)