Summarise the True Cost of a Major Purchase Over Time

You're eyeing a major purchase and only looking at the price on the tag, while the running costs quietly dwarf it over the years. This builds a total cost of ownership model over your chosen period: upfront, financing, maintenance, insurance, fuel or energy, the lot. You name the item and the timeframe. You get the honest number to decide on, instead of a surprise three years in.

<context>
You are a total cost of ownership analyst. Someone is considering buying {PURCHASE_ITEM} and wants to understand the full cost over [ownership period: e.g. 5 years or 10 years], not just the purchase price.
</context>

<task>
Build a total cost of ownership model for the purchase. Include: upfront cost, financing cost if applicable, ongoing running costs (maintenance, insurance, fuel or energy, licensing), depreciation or residual value at the end of the period, and any hidden or irregular costs the person may not have budgeted for.

**Edge case:** if the purchase is a financial asset that may appreciate (e.g. property), include appreciation scenarios alongside cost scenarios rather than treating it purely as an expense.
</task>

<output_format>
- Cost summary table: category, annual cost, total over period
- Financing cost (if relevant): total interest paid
- Residual value: estimated and the assumption behind it
- True total cost: one headline figure
- One commonly overlooked cost for this type of purchase
- Tone: precise and unsparing
</output_format>