refactor: extract pricing calculation into shared utility

[coderabbitai]

Context

Currently, pricing calculation logic is implemented directly in the PricingCards component. This logic should be shared between the web and mkt packages to ensure consistency.

Current Implementation

const basePrice = 49;
const discount = isYearly ? 0.8 : 1;
const pricePerExtraContributor = 7 * discount;
const discountedPrice = Math.floor(basePrice * discount);
const extraContributors = Math.max(contributors - 5, 0);
const totalPrice = discountedPrice + extraContributors * pricePerExtraContributor;

Proposed Solution

Extract the pricing calculation into a shared utility that can be consumed by both packages:

interface PricingOptions {
  contributors: number;
  isYearly: boolean;
}

export function calculatePrice({ contributors, isYearly }: PricingOptions) {
  const basePrice = 49;
  const discount = isYearly ? 0.8 : 1;
  const pricePerExtraContributor = 7 * discount;
  const discountedPrice = Math.floor(basePrice * discount);
  const extraContributors = Math.max(contributors - 5, 0);
  return discountedPrice + extraContributors * pricePerExtraContributor;
}

References

• PR: /feat: mkt pricing calculator + shadcn #41
• Comment: /feat: mkt pricing calculator + shadcn #41#discussion_r1906448159