Supaboat mentioned buying his foamboard from Hobbycraft for economy , that chain sells balsa from an American company so wont be cheap. All the types of construction you mention were probably out of necessity, gum paper etc, To encourage a beginner to build a model on the cheap in modern times I suggest using simple ready available materials. As Ballast says,ply off-cuts, builder`s scrap foam etc. Marionville Models in Edinburgh would be a good source of standard modelling supplies and radio gear, not too far from Bathgate. My first model boat was made from balsa from plans laboriously hand traced by by an adult who could afford the kit, a Veron Thames Police Launch. My first flying model was a Vic Smeed "Tomboy" from a plan purchased the month it was published in Aeromodeller Magazine so I have a reasonable knowledge of balsa. An ED Bee was used in both swopped between the each depending on weather. The Tomboy had floats and I`ve been flying waterplanes ever since, still using balsa. So how do we help someone on a limited budget and mobility to join us in model boating ?