Possibly not suitable as you are concerned about the cost of the Kyam, but worth being aware of Oz tents Oztent RV Accessories Shop United Kingdom | RV Accessories Store United Kingdom | Oztent Accessories Store United Kingdom.
The disadvantage of the Oztent is that packed they are 2m long, but I would have thought this would be OK with a people carrier.
Single poled Tipi and bell tents are also readily set up by one person, but doorways tend to be relatively low for the height of the tent. Additionally, the steep sloping sides of the tipi mean a lot of the tent isn't really that usable.
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These are pure cotton so heavy and bulky, but make for a much more pleasant living space than nylon tents. The walls on bell tents make for more usable space than found in a tipi. They are still easily set up by one person
The tipi that most people think of is the Tentipi Tentipi (UK & Ireland), but expensive. Helsport and Bison are two other makes to look at.
I don't know of UK distributors for these but Helsport are sold here Tamarack Outdoors Tipi / Lavvu Style Tents
Mmmm, I can't immediately find anyone selling Bison tents in the UK any more.
I went through this same exercise recently as my wife has developed a recurring back problem and I realised that I needed to replace our existing tent which was difficult but not impossible for me to put up on my own with something easier. I went for the Tentipi Safir 9 CP, a very expensive option, but it should be a 30 year purchase (lifetime in my case) and as its polycotton, a lot lighter than the 100% cotton bell tents. We had also owned tipi style tents in the past, so we knew what we were buying. But bell tents/tipis aren't for everyone, and hopefully people will come along with easy to set up by one person alternatives.
My Nomad Masai hoop tent allows you to peg out the back, put all the hoops in, and then pull and drag it from the front to lift the tent into position, for you to peg the front out. The problem was that as you tried to put the front pegs in, the hoops would collapse, without someone holding them in position so it could several attempts to get the front pegs in, if pitching on your own. However, this was made more difficult because of the weight of the polycotton outer. I have pitched a similar size/style Eureka tent made of nylon and that was much easier to manipulate. But neither of us can stand camping in nylon tents so that wasn't an option. Hence the Tentipi solution.
Hope you get something sorted. there are several people here using Tentipis and maybe the other tents I mention. Also try The UK Camp Site for Tent and Caravan Campers in the UK as there seems to be lots of people using Bell tents across there (including several threads asking about how easy they are for one person to pitch) and a couple of people using Oztents.