Estimating costs with irregular quantities

[zenwebb]

I'm kicking around the idea of using Kickstarter to help me make a small run of a very simple kit (my first ever) over the summer, as an exercise for me to learn about the kit biz a bit. Right now, I've got early prototypes, BOMs and plans, and am struggling with estimating true costs at scale. In particular, my kit will use mason jars, which come in packs of 12, and 4-40 screws, which are best bought in packs of 100 or so. If the total number of kits is unknown, can one formulaically keep track of the number of 'packs' of parts will be required?

What is a good way of factoring in irregular quantities? Does anyone have any tips for keeping track of this in a spreadsheet (BOM)?

[madworm_de]

Well, I think the first run should cover all costs you have + some profit + ... Once there is a steady number of kits going out, you can adjust to that later.

If the first batch only requires say 50 bolts and nuts, but you can only get them at a reasonable price in quantities of 100, by all means get 100 and add all of them to the bill.

You may be able to afford a loss if you do this as a mere hobby for the fun of it, but not if you actually need the money to come in. Sometimes things go sour, shippings may get 'lost' (cough cough), that needs to be compensated in advance.