Buying a caravan at perm on site campground

I am looking to buy a 1970s Anglo Jackson caravan. Currently without a WoF but I hear they’re reasonably easy to get on caravans. It’s permanent on site at a campground I. Auckland. According to camp rules, We can only use it in holidays and long weekends etc. current camp fees are about $5k per year. The plan is the grandkids stay in hols and future me might rent out my house over summer and stay in the caravan or even do a jaunt in Australia, rent out house, and live in caravan when we come home. We are late 50s. Has anyone done this and what should I look out for? I know that any camp ground is up for removal so permanent doesn’t mean much these days. Any things to look out for? Any advice?