app.controller('TestController', function ($scope, $http, $timeout) {
    $scope.ob = [
        {id: 1, prices: [{count: 2, price: 18}, {count: 3, price: 38}]},
        {id: 2, prices: [{count: 2, price: 18}, {count: 3, price: 38}]},
        {id: 3, prices: [{count: 2, price: 18}, {count: 3, price: 38}]},
        {id: 4, prices: [{count: 2, price: 18}]},
        {id: 5, prices: [{count: 3, price: 18}, {count: 5, price: 38}]},
        {id: 6, prices: [{count: 1, price: 18}, {count: 2, price: 38}]},
        {id: 7, prices: [{count: 4, price: 18}, {count: 1, price: 38}]},
        {id: 8, prices: [{count: 2, price: 18}, {count: 3, price: 38}]}
    ];

    $scope.getByCount = function (count) {
        for (var i in $scope.ob) {
            for (var r in($scope.ob[i].prices)) {
                if (count.indexOf($scope.ob[i].prices[r].count) === -1) {
                    delete $scope.ob[i].prices[r];
                }
            }
        }
        $timeout(function () {
            console.log($scope.ob);
        }, 500);
    }

    $scope.getByCount([1, 2]);

});