Work out your break-even point

Work out the break-even point for {{business}} from my figures, so I can decide whether {{decision}} makes sense. I want to know how many sales I need each month to cover my costs today, how that changes if I go ahead, and how sensitive it is to price and cost changes.

What I sell and at what price (average price per sale, or per product with the sales mix if I have a few): {{prices}}

Variable costs per sale (materials, packaging, payment fees, commissions, delivery):
"""
{{variable_costs}}
"""

Fixed costs per month today, leaving out anything that only starts if I go ahead (rent, wages including my own pay if I take one, insurance, software, loan repayments):
"""
{{fixed_costs}}
"""

Current sales per month, if I have any: {{current_sales}}
What changes if I go ahead (new costs, price or volume changes): {{decision_changes}}

Produce:
1. Contribution per sale: price minus variable costs, with the calculation, and as a percentage of the price.
2. Break-even today: fixed costs / contribution per sale = sales needed per month, rounded up, and the revenue that represents. Show the arithmetic, for example "6,000 / 24 = 250 sales a month, or 12,500 in revenue".
3. With the decision: break-even again including the changes above, side by side with today, and where my current sales sit against each.
4. What-if table, based on today's figures, with the columns Scenario, Contribution per sale, Break-even sales, Change. Include price up 10%, price down 10%, variable costs up 10%, and fixed costs up 10%. Recalculate percentage-based costs, such as card fees, at the new price.
5. Plain-English takeaways: up to 4 bullets.

Rules:
- Use only my figures. If I sell several products, use a weighted average only if I have given the sales mix; otherwise work out break-even for each product separately and say so.
- If loan repayments are in my fixed costs, keep them there and note that this is a cash break-even, since repaying a loan's principal is not a cost in the profit and loss.
- Do not give tax or investment advice, and do not tell me whether to go ahead. Show what the numbers say.

A good answer lets me check every number with a calculator in a few minutes. Keep the text outside the tables under 250 words. If a cost is listed without saying whether it is per sale or per month, ask about it, leave it out of the main figures, and show in one line how break-even changes if it is monthly. If a cost appears both in today's costs and in the changes, count it once and say so.