Decide on how sturdy you want it to be, and what your needs are regarding the sides
A basic pop up could be in the region of £50 - £60 and May of may not include the sides
For a small number of £hundreds you can have the entry level trade gazebo
Then moving up the scale look for hexagonal legs for a stronger frame
Handle the pop up with care, if it doesn’t want to go down neatly then don’t force it, there will be a reason why it doesn’t want to go down - check for the locking features and anything that may caught in the mechanism or twisted.
Use brute force to pack down a pop up and it’s going to be broken quickly
Assembly is recommended for at least two people, but they can be put up by one.
Pull out opposing corners slowly and steadily, and do so lifting the leg in each corner - let them space out ‘naturally’ don’t drag any legs
To extend life it’s ‘best practice’ to remove the roof, but you should comfortably be able to close and pack it with the roof on
(if it’s packed when damp then open it up again at home to dry)
Cheaper gazebos may have tie on sides, the ideal sides Velcro to the roof and zip to each side.
A gazebo with sides included will tend to have two window sides, a plain side and a doored side. With some you can select the mix
If used for trading etc you may prefer plain sides than windows, or windows with a cover flap (so you can shut up shop without everything in view)
Consider how to secure the gazebo - that’s a topic of its own on weights, pegging etc.
Cheap roofs might have loops for guy ropes that will just rip off in strong wind