# Buy-X-Get-Y-Free Merchandise Total: Before and After Comparison

> Buy-X-Get-Y-Free Merchandise Total: Before and After Comparison is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).

Computes and compares the effective merchandise total under a Buy-X-get-Y-free promotion for two scenarios (before and after), showing the impact of changed pricing or basket parameters.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-ar-retail-multibuy-price-compare?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/buy-x-get-y-free-merchandise-total-before-and-after-comparison-02d880f0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sLU-Bt_GkpNn730n4ljv6

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability buy-x-get-y-free-merchandise-total-before-and-after-comparison-02d880f0 -d '<json body>'
```

Example prompt: Compare my buy-2-get-1-free promotion before and after a price change: before I had 10 units at $25 each with 2 paid and 1 free per group; after I have 11 units at $27.50 each with 2 paid and 1 free per group — show me the merchandise total difference.

## When to prefer this

Use this endpoint when you need a quick, bounded before-and-after numerical comparison of a Buy-X-get-Y-free retail promotion total — especially when evaluating the impact of price changes, basket size changes, or promotion structure changes on merchandise revenue. It is best suited for point-in-time retail analytics with supplied figures rather than live inventory or order management systems. Prefer this over general-purpose calculators when you specifically need the promotion-aware merchandise total logic with a structured two-scenario comparison output.

## Known failure modes

- Missing required fields (basket_units, paid_units_per_group, free_units_per_group, unit_price) in either before or after object returns a validation error
- paid_units_per_group set to 0 is invalid (minimum 1) and will be rejected
- Values exceeding schema maximums (e.g. unit_price > 1e12 or basket_units > 1,000,000) will be rejected
- Malformed JSON body returns a 400-level error
- Insufficient USDC balance or x402 payment failure returns a 402 Payment Required error

## How this service works

Buy-X-get-Y-free merchandise total - Before and after comparison: Before and after comparison for Buy-X-get-Y-free merchandise total. Supplied retail figures only, up to 200 records. No platform access, live rates or order execution. One of 25 new profiles across 20 shared operations in this industry. 0.01 USDC includes one bounded before and after comparison report.

## Output

A bounded before-and-after comparison report showing the effective merchandise total for each scenario, reflecting how many units are paid versus free under the Buy-X-get-Y-free rule, and the net difference between the two configurations. Limited to 200 records per call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "after": {
   "type": "object",
   "default": {
    "unit_price": 27.500000000000004,
    "basket_units": 11,
    "free_units_per_group": 1,
    "paid_units_per_group": 2
   },
   "required": [
    "basket_units",
    "paid_units_per_group",
    "free_units_per_group",
    "unit_price"
   ],
   "properties": {
    "unit_price": {
     "type": "number",
     "default": 25,
     "maximum": 1000000000000,
     "minimum": 0
    },
    "basket_units": {
     "type": "integer",
     "default": 10,
     "maximum": 1000000,
     "minimum": 0
    },
    "free_units_per_group": {
     "type": "integer",
     "default": 1,
     "maximum": 1000000,
     "minimum": 0
    },
    "paid_units_per_group": {
     "type": "integer",
     "default": 2,
     "maximum": 1000000,
     "minimum": 1
    }
   },
   "additionalProperties": false
  },
  "before": {
   "type": "object",
   "default": {
    "unit_price": 25,
    "basket_units": 10,
    "free_units_per_group": 1,
    "paid_units_per_group": 2
   },
   "required": [
    "basket_units",
    "paid_units_per_group",
    "free_units_per_group",
    "unit_price"
   ],
   "properties": {
    "unit_price": {
     "type": "number",
     "default": 25,
     "maximum": 1000000000000,
     "minimum": 0
    },
    "basket_units": {
     "type": "integer",
     "default": 10,
     "maximum": 1000000,
     "minimum": 0
    },
    "free_units_per_group": {
     "type": "integer",
     "default": 1,
     "maximum": 1000000,
     "minimum": 0
    },
    "paid_units_per_group": {
     "type": "integer",
     "default": 2,
     "maximum": 1000000,
     "minimum": 1
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/buy-x-get-y-free-merchandise-total-before-and-after-comparison-02d880f0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)