You listed a Gazelle purchase price, not a sale price. They flip them for a profit. The sale price to Gazelle is $110 for a flawless 5s. https://m.gazelle.com/sell/495462-gpid
You can get about $90 more if you sell them privately. I check eBay for actual value and then list them on Craigslist. I've always found them to be quite easy to sell.
Yep, it was the first gold iPhone, but color doesn't typically effect the sale price or allow you to sell it faster. Getting it unlocked by AT&T will usually allow you to sell it faster. Most of mine sell within three hours of posting a Craigslist ad, but I time them to for sale right before a new iPhone launches and the value slightly declines.