The first ounce is 44 cents. Each additional ounce is 17 cents. That would be 78 cents to mail it anywhere inside the US.
The cost will depend upon the size and also the weight of the envelope. Also if it is first class or second class mail, and the country you live in. If you are in UK you can go to Royal Mail website and get the exact price of the cost but you need the weight of the envelope.
The cost to mail a manila envelope will depend on the size of the envelope and the weight of the envelope. The average cost to mail a manila envelope that is 8"X11" is about $2 if the contents weigh less than one pound.
The cost to mail a 5.75 x 8.75 envelope will depend on the weight of the envelope. As of May 2014, the cost to mail a standard letter is 49 cents.
It currently costs 44 cent to mail a regular envelope, which is the price for a stamp.
One Forever stamp, or 47 cents.
It does not cost very much in order to ship a standard piece of US mail in a padded envelope. The cost of shipping standard US mail in padded envelopes can cost as little as $3.
5.25 X 5.25 envelope
depends on the size and weight
1.00$
An envelope with a height exceeding 6 and one-eighths inches, and any square envelope, is non-machinable. Therefore, the rate for first class US domestic postage is $.64.
That will depend which country you are in, the destination of the envelope, and by which method you are mailing it.
About six dollars