If you can afford to take a new one on a lap do it!
If not there are some great second hand ones around.
We did our lap with a 5k second hand camper and had a cracking time.
It all come downs down to budget and where you want to tow it etc, you might need a more robust set up that you can trust rather than a second hand one that might have been neglected.
Our camper was just like new so I could trust it and we towed it everywhere.
Good luck with your choice.
Cheers
Rich