Add special market tier

{
  "error": "<string>",
  "pagination": {
    "limit": 123,
    "order": "<string>",
    "page": 123,
    "total": 123
  },
  "result": [
    {
      "maker_fee": 123,
      "taker_fee": 123,
      "tier": 123,
      "title": "<string>"
    }
  ],
  "success": true
}