public static void SetExchangePrices(JToken prices)
{
    priceLikesSell = Convert.ToDouble(prices[(object)"sell"][(object)"likes"].ToString());
    priceFollowersSell = Convert.ToDouble(prices[(object)"sell"][(object)"followers"].ToString());
    priceRepostSell = Convert.ToDouble(prices[(object)"sell"][(object)"repost"].ToString());
    priceLikesBuy = Convert.ToDouble(prices[(object)"buy"][(object)"likes"].ToString());
    priceFollowersBuy = Convert.ToDouble(prices[(object)"buy"][(object)"followers"].ToString());
    priceRepostBuy = Convert.ToDouble(prices[(object)"buy"][(object)"repost"].ToString());
}

{
  "prices": [
    {
      "sell": {
        "likes": "12345",
        "followers": "12345",
        "repost": "12345"
      },
      "buy": {
        "likes": "12345",
        "followers": "12345",
        "repost": "12345"
      }
    }
  ]
}