score:4
"If I don't feel like a king on this boat, I'm gonna be one mad mo-fo". Sounds like you're setting yourself up for disappointment, expectation wise, but anyway 25 pairs of underwear and socks takes up little room, you could just bring them if it makes you feel better. Self-serve laundry sounds a bit painful as one of the other comments indicated- finding machines that are available and slow drying.
'Room Service" laundry costs actually look pretty reasonable if this blog is fairly accurate and up-to-date. Hotels can be insanely expensive.
Rush service is +50% or +100% of the prices, as it says.