A smaller power without a navy could buy a merchant ship and equip it with containerised missiles. Wartime conversion would depend on having the missiles and supporting systems already waiting in a warehouse. Acquiring and preparing that equipment creates costs before the emergency begins. The cost judgment is that buying an actual warship would probably be cheaper.
Notable Point · 8:08-8:39
Containerised missiles require investment before a war
A merchant conversion for a smaller power still needs stored weapons and support equipment, so an ordinary warship would probably cost less.