Well, I'll only use it occasionally, so I came across older Japanese cameras, like Nagaoka. I'd like to fit in around 500USD (but I'm from Europe).
the one pictured in your first comment is somewhat uncommon: it has a spring back for film holder, but uncertain what kind of dimension, Matuo or Rittreck are common, Toyo are very uncommon.
With back for glass plates holders, they cost very little when bought on Yahoo auctions site. Some proxy buying services have reasonable fees and collect VAT for EU countries, so no extra processing fees.
All my whole plate gear is bought on Yahoo and on Mercari: cameras, backs, holders, lenses, tripod adapters.
Spring back like the one on this Nagaoka are not so common but cheap, bail backs more common on latest camera sets but also more expensive, Toyo back and holders are very uncommon.
It is very easy to make or adapts backs for this kind of cameras, no lathe, no woodworking bench, no plastic printer needed, just simple materials and basic tools
Nagaoka and Tachihara have retaining hooks for the back differents but not much, than the most common kind as in the Konishi, Okuhara and many more no name or brand plate gone cameras.
I have an account on largeformatphotography forum, and the interest for, and in fact just the knowledge about these cameras and related gear is almost nihil.
Spent more time acquiring Japanese vocabulary and language structures in order to be able to search auction sites and literature, than searching for the gear.
if you are a bit tinkerer, Japanese whole plate is the cheapest gear in large format niche. Cheaper than 4x5. These days even FKD 13x18 can cost some money (unless you buy in Russia).
For film I cut from Fomapan 100 and 200 in 18x24, for Retropan from 8x10 as FOMA doesn't make it in 18x24. I also cut from 18x24 xray and I still have a big roll 24cm x 76m of AGFA aerial Aviphot PE200 to cut from.
I have two Japanese whole plate wooden cameras, one with a simple spring back like in your illustration, weight ~2,6kg. Another with an adapted Toyo bail back ~2,9kg.
I can pack a camera with Toyo back and four holders, couple lenses, a changing bag with a wire for tent shape, changing bag is also used as dark bag, couple boards for the lenses, tripod, the very light and small Calcu-Light exposure meter with 10° addon and ground glass spot probe, all inside a cabin luggage sized bag under 10kg or the combo cabin bag + small bag under front seat, 10kg/12kg total, common allowance with several airlines in Europe (Air Baltic, Norwegian, Wizzair, Rossiya, etc).
one of my camera with three kinds of backs and holders, first the adapted Toyo, then a custom bail back I made for the Rittreck kind of holders, last the old back for wooden holders: