Cost of Ships and Siege Weapons

[MSB]

The problem, in my opinion, is that it is currently more economically viable for me to ignore three or four one ship blockades than to actually smash them all.

That is true, however one tactic to avoid the problem of blockade is to take all of the enemy's naval ports off them before you take the rest of their empire. You do get a few blockades at first, but eventually it all stops and trade can carry on as if the war had never begun henceforth you don't have to "smash" any blockades anyway. Even better it stops you from having to use too many ships while you are at war with the naval faction.