1) Exotic weapons and armor can be bought in WvW for 1 gold + badges if you have any badges.
2) WvW vendors also sell rare armor and weapons for Karma, but NOT trinkets. So, I usually buy exotic trinkets on the Trading Post if I’m strapped for cash, and go for rare armor and weapons.
3) If you are strapped for cash, you might want to consider getting a really cheap armor off the Trading Post, such as Cleric’s which was about 1 gold when I bought it. Having a full set of exotic armor and weapons will make you stronger than having a couple of exotic pieces with your preferred stat and the rest of your gear being stuck as Masterwork and Rare.
4) As someone else already mentioned, the equipment sold by WvW vendors cannot be salvaged. So, if you don’t want to waste your money then just buy some really cheap runes and sigils to put in them. There are some runes and sigils on the trading post that are pretty useful that you can get for very cheap. They won’t give you the “max deeps” but they will increase your effectiveness by a lot. If you put expensive runes and sigils in the vendor gear, you will eventually have to trash them and you will never be able to get them out. So, putting runes in there that cost six gold pieces is a complete waste, especially if you eventually intend to replace your armor and weapons with ascended. Always put runes in there that cost a few silver and not a few guild wars 2 gold.
5) All ascended trinkets can be bought for laurels (+ ectoplasm for earrings) and if you plan to WvW you might want to get the inscriptions from the WvW vendor which adds five to a stat and increased/reduced damage to/from WvW guards. With full inscriptions, that’s 3% reduced damage from guards and 2% increased damage to guards.