I'm not keeping tons of paper receipts. No room to save all that paper. I set mine up in an OpenOffice spreadsheet.
Sheet 1: I have columns for...
DATE
SOURCE (where bought)
DESCRIPTION (to keep track of what i bought)
COST (with tax) running total at bottom of page
MATERIALS (without taxes) running total at bottom of page
VEHICLE COST & REPAIRS (cost of the bus shell plus repairs made to the actual bus not related to conversion) running total at bottom of page
PAINT running total at bottom of page
PLUMBING running total at bottom of page
APPLIANCES running total at bottom of page
INSULATION running total at bottom of page
WOOD & MATERIALS running total at bottom of page
ELECTRICAL/BATTERY SYSTEM running total at bottom of page
TOOLS (wanted to keep track of what I bought to use on the bus) running total at bottom of page
LIGHTING running total at bottom of page
HEAT/AIR running total at bottom of page
MISCELLANEOUS running total at bottom of page
Sheet 2: this page shows what I still need to buy. I keep the date/prices updated monthly so I don't end up with a nasty surprise. Once bought, I delete the row. Everything is in subcategories (Electrical, Walls, Bay Boxes, Showerstall, Cabinets, Plumbing, LP, etc). Stuff is set up more in project groups that anything else.
DATE
DESCRIPTION
PRICE EACH
QTY
COST
SHIPPING OR TAX
TOTAL
NOTES (location of where I found the item. I usually have more than one source so each source for an item (like lights) will get it's own entry/price/source.
At the bottom of the page I have
SUBTOTAL (deleting out QTY results in the items I will most likely buy with out having duplicates including the ones I won't)
"ALREADY SPENT" (from sheet 1... requires an entry that looks like this... =Sheet1.E96)
TOTAL of subtotal & Already spent. As of right now, I'm looking at a potential TOTAL investment of $3315.20, not counting the cost of the bus shell or repairs made to the bus. This does include future purchases.)
Sheet 2 also includes notes I've made (Merge Cells to make one large cell).
Sheet 3 has a couple mini spreadsheets. A few have been set up for figuring power usage for various appliances. I have a running spreadsheet dedicated for the Hydronic system (both heat/air) since it is being put together piece by piece as we get the $$ to do it. I have the results for that on Sheet 2 (Heat/Air Chiller.... =Sheet3.C36). It simply lists the individual component, have/buy, cost, Notes (where to buy). If I have bought the component, the item bought is entered on sheet 1 (Heat/Air column), $0 is entered on Sheet 3 and the remaining estimated total shows up under "heat/air chiller" on Sheet 2.
Building the BlueBird Conversion Costs spreadsheet was much easier than putting together my Fulltiming Budget Non-Budget Spreadsheet. It's 14 sheets and 12 of the sheets link back to Sheet 1. It's a budget spreadsheet I set up because I wasn't sure of where to start with a budget so this one I just fill in monthly and it extrapolates a monthly budget for next year based on actual numbers. Helps to know what we spend $ on. It's also how I discovered how much $ we spent on groceries one month ($700+) because we were buying every few days.