What this guy said. I could go into different niches of different waxes. The new AG HD is a great wax. They really smashed it, but it won't feel special.Not one I've tried but I'm sure @gally and @Christopher both rate Zymol Carbon, Pretty sure you'll find that at around £50.
I've always liked Britemax Vantage which should come in under your £50 budget.
I would be waxing a transporter with a spray sealant. f**k using my carbon or Glasur on a transporter! Get some brilliant shine detailer.
Oh and a wipe down product I recommended recently. Infinity wax rapid detailer, impressed me a lot which is so rare these days!
Spray sealant for the transport. If you fancy mixing it with another QD then sonax brilliant shine detailer, I haven't tested turtle Wax yet. Or a big bottle of gtechniq C2V3, will even dilute a little.