Here is the link to the Airbnb listing:
https://www.airbnb.com/rooms/32088620

The price is around $45 a night, give or take a few bucks. You can find the link to the listing in the description. Just a heads up, if you're planning to stay during Semana Santa, which is from April 3rd to April 9th, it's gonna be a bit more expensive.

So, I stayed there for a short while and now I'm moving to another apartment in Cartagena. The big question is - is it worth the price? I'd say, yeah, it is. It's got two air conditioners that work just fine, a kitchen, and a bathroom that does the job. There are plenty of beds, too. 

The place is in a well-known building called Nuevo Conquistador, right in the heart of Boca Grande in Cartagena. It's pretty secure, or at least as secure as you can expect in this city. It's got a key card lock system, but I think there's still room for improvement when it comes to security. The balcony door could use a better lock, for example. Of course, break-ins aren't too common, but it's something to keep in mind.

The apartment comes with some nice amenities like a fridge, a gas stove, and even a coffee maker. The TV has Colombian cable, but no Netflix. That didn't bother me, though. I just hooked up my computer to the TV, switched the input source, and I could watch whatever I wanted through the internet. The Wi-Fi connection is pretty strong, by the way.

To sum it up, this Airbnb is a pretty good deal for $45 a night. Just remember that the price goes up during Semana Santa and Carnaval.