Hi! I am also lookin to put on a budget wedding this year, so thanks for starting this thread.
I think the most important thing is to figure out what is most important to you and your fiancé so that any extra money in the budget goes to what matters most.
As for the dress… I would look at David’s Bridal before thinking of ordering online, DB has some pretty cheap dresses that are still quite pretty.
Other ideas for saving money
Flowers: consider having the bridesmaids carry a single long-stemmed rose, or maybe even two or three. Getting in-season flowers for everything and having finding ways to make your flowers stretch, placing the heads of a few gerber daisies, say, so that they float on water, maybe with candles next to the container, maybe some rose petals scattered around and you could get some nice centerpieces without having to pay a ton on flowers. Or if you really like the idea o having floral centrepieces you can order the flowers bulk online and pu it together yourself.
See if any friends have a large enough yard where you could have the reception, or see if there are any local halls or parks that you could probably rent more cheaply. If it’s outside though you will probably need a backup in case it rains, some sor of tent or covered area.
Yeah, basically see what your friends and family can help you out with. Also, as much as possible avoid looking for things marketed as for a wedding, the label “wedding” automatically increases the price on anything. Which is why if you can buy a nice cake for a “family gathering” you’ll probably get a better price.