Get a subscription version item

curl --request GET \
  --url https://api.alguna.io/subscriptions/{id}/versions/{vid}/items/{ref} \
  --header 'Alguna-Version: <alguna-version>' \
  --header 'Authorization: Bearer <token>'

{
  "bundle_id": "bun_abc123",
  "items": [
    {
      "price": {
        "billing_direction": "arrears",
        "billing_interval": "monthly",
        "charge_on_contract_start": false,
        "currency": "USD",
        "fee_type": "fixed",
        "type": "fixed",
        "billing_frequency": "recurring",
        "discount": {
          "amount": "10",
          "duration_type": "fixed",
          "type": "percentage",
          "duration_unit": "months",
          "duration_value": 6
        },
        "display_order": 1,
        "expression_pricing_model": {
          "charges": [
            {
              "billing_direction": "arrears",
              "description": "API usage charge",
              "quantity_expression": "usage.api_calls",
              "unit_price_expression": "0.01"
            }
          ]
        },
        "fixed_pricing_model": {
          "price_per_unit": "500.00",
          "total": "500.00",
          "units": 1
        },
        "graduated_percentage_pricing_model": {
          "tiers": [
            {
              "min_units": 0,
              "fixed_fee": "10.00",
              "max_units": 10000,
              "percentage": "2.5"
            }
          ]
        },
        "graduated_tiered_pricing_model": {
          "tiers": [
            {
              "min_units": 0,
              "fixed_fee": "10.00",
              "max_units": 10000,
              "price_per_unit": "0.02"
            }
          ],
          "units": 10
        },
        "maximum_spend": {
          "amount": "500.00",
          "period": "monthly"
        },
        "metric_ids": [
          "<string>"
        ],
        "minimum_spend": {
          "amount": "500.00",
          "period": "monthly"
        },
        "prepaid_fixed_tiered_pricing_model": {
          "overages_charge_interval": "monthly",
          "prepaid_units": 50000,
          "tiers": [
            {
              "min_units": 0,
              "fixed_fee": "10.00",
              "max_units": 10000,
              "price_per_unit": "0.02"
            }
          ]
        },
        "prepaid_tiered_pricing_model": {
          "prepaid_units": 50000,
          "tiers": [
            {
              "min_units": 0,
              "fixed_fee": "10.00",
              "max_units": 10000,
              "price_per_unit": "0.02"
            }
          ]
        },
        "tiered_percentage_pricing_model": {
          "tiers": [
            {
              "min_units": 0,
              "fixed_fee": "10.00",
              "max_units": 10000,
              "percentage": "2.5"
            }
          ]
        },
        "tiered_pricing_model": {
          "tiers": [
            {
              "min_units": 0,
              "fixed_fee": "10.00",
              "max_units": 10000,
              "price_per_unit": "0.02"
            }
          ],
          "units": 10
        },
        "trial_period_days": 30,
        "unit_pricing_model": {
          "price_per_unit": "0.05"
        },
        "volume_percentage_pricing_model": {
          "percentage": "2.0",
          "price_per_unit": "0.05",
          "fixed_fee": "5.00"
        }
      },
      "product_id": "prod_abc123"
    }
  ],
  "price": {
    "billing_direction": "arrears",
    "billing_interval": "monthly",
    "charge_on_contract_start": false,
    "currency": "USD",
    "fee_type": "fixed",
    "type": "fixed",
    "billing_frequency": "recurring",
    "discount": {
      "amount": "10",
      "duration_type": "fixed",
      "type": "percentage",
      "duration_unit": "months",
      "duration_value": 6
    },
    "display_order": 1,
    "expression_pricing_model": {
      "charges": [
        {
          "billing_direction": "arrears",
          "description": "API usage charge",
          "quantity_expression": "usage.api_calls",
          "unit_price_expression": "0.01"
        }
      ]
    },
    "fixed_pricing_model": {
      "price_per_unit": "500.00",
      "total": "500.00",
      "units": 1
    },
    "graduated_percentage_pricing_model": {
      "tiers": [
        {
          "min_units": 0,
          "fixed_fee": "10.00",
          "max_units": 10000,
          "percentage": "2.5"
        }
      ]
    },
    "graduated_tiered_pricing_model": {
      "tiers": [
        {
          "min_units": 0,
          "fixed_fee": "10.00",
          "max_units": 10000,
          "price_per_unit": "0.02"
        }
      ],
      "units": 10
    },
    "maximum_spend": {
      "amount": "500.00",
      "period": "monthly"
    },
    "metric_ids": [
      "<string>"
    ],
    "minimum_spend": {
      "amount": "500.00",
      "period": "monthly"
    },
    "prepaid_fixed_tiered_pricing_model": {
      "overages_charge_interval": "monthly",
      "prepaid_units": 50000,
      "tiers": [
        {
          "min_units": 0,
          "fixed_fee": "10.00",
          "max_units": 10000,
          "price_per_unit": "0.02"
        }
      ]
    },
    "prepaid_tiered_pricing_model": {
      "prepaid_units": 50000,
      "tiers": [
        {
          "min_units": 0,
          "fixed_fee": "10.00",
          "max_units": 10000,
          "price_per_unit": "0.02"
        }
      ]
    },
    "tiered_percentage_pricing_model": {
      "tiers": [
        {
          "min_units": 0,
          "fixed_fee": "10.00",
          "max_units": 10000,
          "percentage": "2.5"
        }
      ]
    },
    "tiered_pricing_model": {
      "tiers": [
        {
          "min_units": 0,
          "fixed_fee": "10.00",
          "max_units": 10000,
          "price_per_unit": "0.02"
        }
      ],
      "units": 10
    },
    "trial_period_days": 30,
    "unit_pricing_model": {
      "price_per_unit": "0.05"
    },
    "volume_percentage_pricing_model": {
      "percentage": "2.0",
      "price_per_unit": "0.05",
      "fixed_fee": "5.00"
    }
  },
  "product_id": "prod_abc123"
}