How about $55
oil caps, a pair of handles for $50, $100 here and $100 there. Then it get to be $200 items and $300 items.
I think you can double the kit price and be close.
In our bunch we have paid $800, $2250, $2800, $4500 for paint and some have paid as high at $13,000.
Some have build motors for a couple of thousand and some have paid over $10,000.
just don't tell the wife what stuff cost or it will double
Dwight