(1) Do not send a post card query with your novel's website, unless it has a postcard SASE, and those don't exist. We will not check your website. We will not even like you very much for your total lack of effort. If you invest postcard SASEs and they move into general circulation as a product, we can talk.
(2) That said, there is no need to spend more than 82 cents on a query unless you live out of the US or this is an old post and the price of stamps has gone up. 41 cents for the original, 41 for the return. If you want to include a synopsis or the first 5 pages, you can get them into a regular envelope. There is no need to waste money sending the query a special speed, through a courier service (it's been done), or sending it in a nice presentation folder that cost you $5.00 to send. We only care about your manuscript and how you describe it in the query. It will go into the pile like everyone else's when it arrives, so save yourself some money and don't bother. For a letter envelope, the rates are:
Ounces and Cents Above 1 Ounce/.41c
Really, if you're going to be submitting, query widely, and don't spend a lot of money doing it if you don't have to. The rejections will not sting so badly if you're not down a hundred bucks.