For the most part, gazebos tend to be on the higher side as far as the expense is concerned. This includes purchasing a pop-up gazebo or having the thing assembled from scratch. While it is indeed possible for you to build a gazebo by yourself, it can get technical at some points so it's not a DIY job for everyone.
What that means is that you will almost certainly end up having to hire someone to build it for you, which of course adds to the cost. Because most gazebos are barebones as far as luxury features are concerned, you’ll have to add those in as well on top of the purchasing and installation costs. In general, gazebos end up being costlier than similar outdoor setups such as decks or patios, but of course, you get a lot more for that money than most decks can muster.
Maintenance is another challenge. Much like your home, a gazebo is a wood-framed structure, which means it is vulnerable to the elements. Over time, water will cause the growth of lichen and mold and will cause wooden gazebos to rot. This means that you’ll have to practice regular maintenance in order to keep your gazebo in good shape.
Otherwise, expensive damage could result if your gazebo is neglected. You can of course choose different materials such as metal, but this comes with its own downsides. A metal gazebo will get a lot hotter in the summer for instance. Some prefabricated gazebos have the low build quality, so be sure to avoid those so you don’t have to contend with excessive maintenance.
Gazebos tend to be fairly significant in size, and this combined with the fact that most models require a concrete pad to sit on means they will take up some space in your yard. For this reason, it might be a bit difficult to find an optimal place for it, since you’ll want to put it somewhere easily accessible but not where it is causing obstructions.
This isn’t an issue per se, but you’ll feel that it takes up room if you have limited space in your yard, to begin with. Also, a big gazebo may look a bit out of place if you have a smaller yard. Porch gazebos do exist, but modern gazebos generally are meant to be set away from fencing to allow for a full open-air setup.