Engagement rings, on the cheap side

Overstock.com

Etsy.com

Ebay

Check out Diamond Nexus if you're open to the idea of a lab-created diamond. FH purchased my ring from them and I absolutely love it! Not only is it guaranteed conflict-free, technically it's still a diamond and looks way more expensive than it actually cost. I have a gorgeous 1ct stone for just shy of $800. There are pros and cons of course but I definitely recommend looking into it if you're on a tight budget but desire a quality stone.

Be prepared to get what you pay for. Verragio rings have a lot of small intricate details and for them to be able to hold up you need a specific quality of material. A knock off or replica will likely have those details with thin metal that will probably break.

ETA words are hard

I'm unfamiliar with verragio, but when I was showing DF rings I liked, I found my "ideal" engagement ring for about $650 on Adiamor.com. I actually wanted a much smaller solitaire than DF got me though, so an $800 budget wouldn't have been an issue for me.

Definitely check Etsy.

We got my ring off etsy. Its a 2 karrat and it's absolutely beautiful. Its cubic zarconia but you can't even tell it's not a diamond. Everyone thinks it's real.

Kay jewelers or even Littmann will work with you

Definitely check out Etsy! Also, you should look into morganite or moissanite stones, as opposed to diamonds. They are becoming pretty popular for "untraditional" brides! :-)

Etsy! I love my ring and it was about $150 shipped on Etsy.

I found you an example! This one is just barely under your budget, but it reminded me of verragio. Etsy is great, I'm sure you'll be able to find something you love, under budget! You'll just have to do some looking around, and definitely check out the shops reviews before making any purchases! I've found that in most cases, the reviews are pretty accurate.

Look at moissanite stones. They are absolutely beautiful and you can't tell any difference between them and a diamond but they're MUCH cheaper!

Etsy is amazing!

Zales

Look at non-traditional stones. I have morganite, the stone is a little smaller than a 1 1/2 ct diamond, and it was under 500.

Agree with Etsy! We got mine from Etsy and it is beautiful. Also agree with looking at non-diamond stones. Like @Melissa, I also have a morganite ring and I get compliments all the time on it.

Gemvara.com! My ring was under 500 and we got to design it!

Amazon

Look at Mossianite! I love mine more than I can express, and It is much prettier than a diamond! My cousin held it up next to a diamond of similar size and cut, and my stone was soooooooooooooooo much brighter and clearer