No. Most of the time, you will get the shipping preference that you chose but it is never guaranteed. Sometimes (usually less than 2%), we will be unable to honor your shipping preference and you will matched against it. If you live in a small country or a country with very few participants, there is a higher chance that you will be matched against your shipping preference if you have chosen domestic shipping. When signing up, you will be expected to honor completion of the exchange, even if your match does not meet your shipping preferences.
As Redditgifts does not have any rules against shipping a gift directly to your giftee from a vendor, one thing that you can try if you are matched against your shipping preference is purchasing a gift from a website located within your giftee's country and have it shipped directly as a way of cutting down on shipping costs. Etsy is great for this because you can narrow down your search to merchants that are super local to your giftee. If you'd like to add a little personal touch, you can always send along a separate card or note!