Trinkets and weapons aren't that hard to get ascended versions of.
Just doing your dailies/monthly will net you a 3 of your trinkets over time.
Back piece you can either buy with gold, or earn through fractals play.
The other two trinkets are best done by doing guild missions, and there are pleanty of guilds set up that run guild missions every day, pop along to those once a week for a month and that's those done.
Weapons are a bit of gold sink to get to lv500, though if you make stuff like Destroyer weapons, you can actually level to 500 without spending a penny. It just takes a while to get your money back while you wait for them to sell on the Trading Post.
Once at lv it's only about 75g for an ascended weapon if you buy all the parts, or if you have some stuff already farmed you can offset some of the cost.
Armour on the other hand is a damn hard to get a full set of. Very expensive to level to 500, then you need to spend a lot of laurels, gold and karma just to get the recipies, then you need a crapton of materials, a good chunk of skillpoints for Auger stones, etc. You are easily looking at over 600g for a full set of Ascended armour... which is rather painful!
Luckily it's by no means required to do any content. It's just a goal for people with too much time and too much gold