Manufacturing to Retail Cost Calculator

I am trying to make an EASY Manufacturing Cost to Retail pricing calculator. This calculator would have ability to include cost of goods, labor, markup etc of components manufactured and sold as retail products, example: small bookshelves versus large bookshelves or cabinets all have different materials (wood types, stain etc) in determining the final retail product costs that would reflect time of labor hours involved in producing to determine final retail costs. Should be simple in Excel 2000 (my version). I have the basic template created and have used Data Validation Drop Down Lists and utilized LOOKUP function. While my knowledge is limited in Excel, I am frustrated as how the LOOKUP function works, I can only get it to work where in the formula, the costs per unit are input manually, whereas I would prefer to have the data input automatically from columns of calculated wholesale cost plus markup per square foot data, ie: =lookup(A1, X1:X30, Y1:Y30) but get errors when doing this. Instead this works: =lookup(A1,{"pine", "oak", "birch"},{"3.99","7.87","5.15"}) and using this cell (A1) in my calculations for including the square foot costs in the final retail calculations. While this seems to work, it is not easily modifiable as costs change rapidly and would like to easily input the cost per square foot of the different woods in their own cells rather than in the formula calculation of the lookup. Hope that makes sense..... any suggestions? perhaps lookup is not the best function for what I am attempting? - sample file is attached, light green are notes of where my data is located. Thanks....