Caleb - apologies for the unkindness below. This post will be deleted as soon as you ask me to on the forum or via a PM or email (my email address is in my signature at the bottom of every one of my posts).
It's possibly both, and some more to boot.
1) Price: the most expensive 0.9x H/SI2 princess cut listed on the Diamond Finder here is less than $4,000. A similar looking setting on Blue Nile is about $1100.
Put the two together, and you end up with a bill below $5000 for a new item... and neither the diamond nor the setting is the cheapest of their kind.
You could put together a ring that costs less than $3000 and whose description reads fundamentally the same as yours. I'm not saying it's as nice - but if I read two ads with the same description, and one is "new for $2800" and the other is "second hand for $6000", which one am I going to be more interested in?
2) Marketing: you are using two basic props for your sale here: a single photo from which one can barely make up the shape of the sapphires (are they hearts? ovals? pears?) and the diamond is relegated to near invisibility. The second prop is a poor quality scan of an appraisal by an unknown jeweller quoting an unrealistic replacement value (see above) and providing no information beyond the bare minimum (what does "sapphire of AA quality" mean? Are they treated? Natural? Who is calling the diamond H/SI2? The jeweller? GIA? EGL-Israel?).
You are selling in a market where professional sellers can provide buyers with facilities such as free shipping, guarantees, return periods, professionally taken photos and videos, financing, independent lab reports on the quality of stones, ... It's understandable that you as a private individual cannot provide any of those, but then your advantage has to be somewhere else; it's usually price (see above again), or - if you are good at selling - at least document your piece properly and jazz it up with quite a few good quality photos.
Trying consignment is not a bad idea, but you need to make sure that the consignor is realistic; offering you to retail at a high price is not a sign that they can get that price. You would be much better off choosing a consignor that has a proven history of shifting stuff, even though your take may be lower.
3) There is a fashion aspect too, and at the moment 3-stone rings aren't particularly popular. Add to this that selling a second-hand engagement ring is never an easy task. For some reason, a new ring is shiny and blingy, a 100 year old ring is romantic, but a 2 year old ring is neither.
1) Understand what you have. Get a proper appraisal for the purpose of resale. This is not a public document; it's for you to decide what you have and what is a reasonable value/price to ask when selling in different ways.
2) Decide whether you need further documentation to help with the marketing and selling (lab reports). The appraiser can help you decide that, and assist with the logistics if required. If you are going the direct
3) Set your selling strategy and channels: pawn shops aren't necessarily a bad choice, depending on what the appraiser tells you.