One official reason for the price hikes is to finance new ships, as a few much-publicized mishaps earlier this decade finally led to the forced phasing-out of the 30+ year old (and fully amortized) boats which kept the prices low.

You won't find sizeable discounts on boat tickets, but perhaps slightly lower prices on a smaller competitor with few ships and routes. I do agree the ticket prices have gotten out of hand, and made island-hopping a financially different proposition altogether. Then again, there was all that post-Olympic talk of catering to higher-end tourists, a trend that may have started when the closure of the overland Balkans route kept budget northern European visitors at bay in the 90's.