How about we just have 3 tiers of ships (and price them accordingly)?
1. The practically free tier and
2. The ships that cost credits tier and
3. Special ships
Tier 1 - basic tool of rp and basic pews - can be set up by anyone within a day and still be competitive with ships of its class, eg any LF/HF/Freightor
Tier 2 - ships that are still free (as in freedom) for anyone to set up, but cost credits to purchase and/or operate and the only way you can possibly have such credits is to be on the server for a while, ensuring that these advantageous ships will not fall into the hands of new players since newbs aint got dough. examples will include bombers, 5kers and low level caps
Tier 3 - Anything that requires official clearance (eg faction member or SRP) to use. Battleships, certain faction ships, anything considered OP.