i just did the deck drains and hoses myself. it was about a day job and a definite pain. for what its worth, i didnt enjoy doing it, but i would do it again before paying someone else to do it unless they would do it for less than $300.
what made it much easier is two things. 1 - i am 6'0" and 160lbs. tall and thin is good for this job. 2 - i cut up sections of pool noodle to put on the stringers so i could lay on them under/behind the transom seat.
edit - another thing that helped was using an oscillating cutting tool to cut the hose off the through hull fitting. i dont think i would have been able to pull them off