In Germany, cheaper pop-up tents like this are quite popular for festivals. I would never buy one, though, for the following reasons:
Every tent of those I have seen have been very prone to breaking. A friend of mine just discovered his (brand new one) was broken when he arrived on the campground. Because the poles are fixed inside you can´t even improvise and repair them with duct tape.
They are often more expensive than comparable cheap tents.
Setting up a modern, regular tent, even a very cheap one, is done in five minutes. Not that much of discomfort, especially compared with repairing broken poles on a throw tent.
They often have a strange form when packed (big, wheel-shaped), which can´t be fit in any backpack. Probably not a problem if you get there by car, but for public transport or hitch-hiking or if you have to walk to get to the campground I wouldn´t like it.
I would strongly advise against buying any pop-up tents. Many festivals, although short and not comparable with "real" outdoor use, are a rough ground where many things can break due to alcohol and other drugs. And these tents are ridiculously unstable.
The tent I have used for many festivals without any problems is a standard two-person iglu tent like the one shown below, available for around 25€, well below your price margin. It is easy to set up (5 minutes), more robust and cheaper than pop-up tents and gets the job done. You will have to look for a reseller on your own, though, but probably just searching for iglu tent will do the job.
For ecological reasons, you might consider buying a used tent, so you don´t throw away something brand new.