This is a lot of money on a big purchase. You need to think about what you really want. Breast bar or not, stallion stall or lockers, not both. Jump guard or escape door, solid wall or emergency back door.
Go and look at lots of nearer ones to get feel for what your money buys.
You will need to get into the gritty bits and look under the floor, prod into the bottoms of everything, inside lockers, check the tyres, check out the previous mots for repairs.
Clocking and mileage blockers are rife in work vans that have been converted into horseboxes and £20k added to the price.
Do not be fooled by a nice paint job. Stick with a well known mane, John Oats, Bloomfields, Equimark, avoid Equitrash.
Hire one to make sure your horse likes it and fits ok.
Get a payload certificate or weigh it yourself, some vans have as little as 650kg payload and with horse driver and tack on are well over 3.5t.
Dont think because its at a fancy dealers they have spent a penny on it. Find everything wrong with it and get them to fix it before you take it home.
If it has living with gas get a full habitation inspection. If you are settled on one definately get it inspected and expect them to find things. Dont believe a word you are told, test it, check it, drive it. Be that annoying person.
I saw so many 10-15k aged 2006-2016 boxes that were pure rubbish, deathtraps, rotten floors, flimsy partitions, leaking ramps that were soft, leaking gas cookers, rusted out brake and fuel lines, awful suspension with rattles, knocks and banging over the smallest bumps, juddering brakes, knackered engines, blown turbos, dodgy electrics.
We bought the most beautiful looking campervan, FSH,low miles, reputable conversion, looked pristine and shy of £40k. We have spent ££££ on repairs in 6 months as its only when you get it home and use it you find out what you really have. The windows dont open, electrics only work on certain days, central locking has a mind of its own, gas leaks, windows leak, bed wont roll out, poptop leaks, heater hardly heats and cuts out. Changing the gas bottle is a pig, new leisure battery needed, turning the seats is almost impossible, new brakes, springs x6! drop links, hand brakes cables, the list is endless.
Beware anything old, 2008-9 boxes are rusting out and junk.
Be careful and haggle, so many grossly overpriced.
Friends bought box and cant get horse in it. Others bought and have spent £££ keeping it going.