Kris the Handyman, just a couple of extra points, the reason you should always use brass machine screws rather than steel or stainless is that down the line someone will probably have to remove them, and decades in a marine environment can often make them difficult to remove and they can snap. Now a stainless or hardened steel fixing snapped going into mild steel is very hard to deal withas the fixing is harder than the surrounding steel and almost impossible to drill out, best bet in this situation is to wack it with a punch and try to shatter it. On the other hand a brass fixing into mild steel is easy to drill out as the brass is softer than the steel.
On the topic of pricing, let me tell you a real life story from a couple of months ago, a customer wanted a shelving unit attached to the cabin wall above the gunnels. If I were to have given a quote it would have been based on buying the oak, planning and preping it, cutting four dovetail corners and four rebates, the back of the unit scribed into the irregular shape of the boat and then screwed into the battens. However here's what actually happened. I located the battens and realised that they were too rotten to take the screws, so I removed the panel and realised that the box section of the cabin frame was rotten, so I removed the steel box and replaced with new box section (so now I'm grinding and welding not wood working. As I try to weld on the box section is becomes clear that half the steel cabin sides are rotten and have been made out of filler, so I have to get out the plasma cutter and remove a section of the steel cabin side and replace with new steel plate. Next I have to prime and paint the new steel plate and attach new battens to the new box section and replace the interior wooden panel, which now needs recutting as the boat has changed shape (only slightly, but enough). I then replace the highly flammable insulation from the 70s with kingspan and replace the wooden panel. Now I have to rescribe the shelves as everything has moved and screw them to the wall.
Now this was a particularly annoying job, but that is not an unusual set of events in my trade, if I had given a firm price I would have been literally paying for the materials out of my own pocket and had two days labour money for a weeks work. If you intend to get into working on boats, bear this in mind and protect yourself. Good communications with the customer helps, and if they seem like a dick when you first discuss the work, walk away
