Small version with 2 different filters 40€, big version with 4 different filters 80€. All come without any kind of carry case / pouch. A bit expensive and lacking for that price tbh
I ordered a custom set a good time ago (months before the existence of this community) and the experience was comparable to yours.
I choose white mbk pbt and the laser engraving was really sharp and looks very good! Shipping was quite fast for me (8 days or something to Germany) but back then VAT was no accounted for during ordering (which I was informed of, no suprises there). So I had to pay VAT after receiving the package. Don't know how it's currently being handled though. Simon was also really responsive, so all in all a quite good customer experience.
The Cheapino gets quite some love recently :D Saw a couple posts in the last weeks, really cool! I too built a Cheapino for myself and a friend who wanted to try out these ominous "ergo mech keyboards" 😁
Wow, really cool :D I'm wondering why you went with a straight line for the thumb keys instead of going for a curve (which so see with a lot of ergo keyboards). Is there any general benefit or is it just more comfortable for your hands?
That's a really interesting case design too! Cool to see that you're taking into account that one might bring it into the office or so and needs a "travel" case as well.
I also own the Cheapino and made myself a keymap which is fully working. You can have a look at it here. Hooe that helps at least some bit.
Regarding the qmk toolbox: You can take the json file from one of the keymaps in tompis qmkfirmware repository and upload it in qmk toolbox. Then you can have the correct layout and you can configure it to your liking.
It's pretty straight forward though you need some soldering skills, especially for the little usb c connector. I used this site: Cable Guide in combination with YouTube videos of Cruzctrl.
In short: You need wire, paracord (for sleeving), optionally techflex (for the shine), some heat shrink, usb connectors and any connectors you'd like to put in between (in my case gx16 aviator). Then you sleeve the cable, put techflex on, solder the connectors, apply heat shrink and you're done. Though that's just a really short write up. It's not overly complicated but also not as easy as it sounds.
Leo from beekeeb offers pre-build split keyboards like this one: https://shop.beekeeb.com/product/pre-soldered-wireless-dao-choc-ble-keyboard/ and it's within your 350$ range.
It should check all your boxes except a dongle and rgb. Regarding the travel case: He even offers a soft travel pouch in the store.
RGB on a wireless split keyboard needs a pretty big battery to have more battery life than a day or too, so it's difficult to find both rgb and wireless in a pre built one without raising the costs. Also some LEDs draw constant power without even being on which also adds to this issue.
Small version with 2 different filters 40€, big version with 4 different filters 80€. All come without any kind of carry case / pouch. A bit expensive and lacking for that price tbh