How to post JSON formatted file to Shopify in C# by development shop

I'm trying to create new/update products by passing a JSON (example.json) formatted file into my shop in C# .NET.

Is it possible to do something like

dynamic createProductResponse = client.Post("/admin/products.json", "c:\example.json");

Where the example.json files contain all the updated/new products. Currently, the only thing that works is passing a JObject like this:

JObject obj = new JObject
                    {
                    {"product", 
                        new JObject{
                            {"title", "Shoes"},
                            {"product_type", "Men"},
                            {"id", "1234566"},
                            {"published_at", new DateTime(DateTime.UtcNow.Ticks, DateTimeKind.Utc)},
                            {"vendor", "Vendorizer"},
                            {"variants", new JArray{
                                new JObject
                                {
                                    {"barcode", null},
                                    {"compare_at_price", "100.00"},
                                    { "created_at", "2013-08-04T10:43:20-07:00"},
                                    { "fulfillment_service", "manual"},
                                    { "grams", "100"},
                                    { "id", "342493891"},
                                    { "inventory_management", "shopify"},
                                    { "inventory_policy", "deny"},
                                    { "option1", "DARK BROWN"},
                                    { "option2", "7"},
                                    { "option3", null},
                                    { "position", 1},
                                    { "price", "75.00"},
                                    { "product_id", "149743231"},
                                    { "requires_shipping", true},
                                    {"title", "DARK BROWN / 7"},
                                    {"sku", "SKUTHING12345"},
                                    {"taxable", true},
                                    { "updated_at", "2013-08-04T10:43:20-07:00"},
                                    { "inventory_quantity", 5}
                                },
                            }},
                        }
                    }
                 };

Am I approaching this incorrectly?

I can obviously update/create new products this way, but it's rather tedious. Since I can retrieve a JSON file of all my products, I was thinking there's a way to also upload a JSON file with the changes.

Thanks for any help you can offer!