Hi Arix. I'm also a new member, but have lurked a while, and have been into mechanical keyboards for years. I can be as cheap as they come, so it still seems to me that it makes a lot of sense to find an existing secondhand keyboard that you like the build/style of and just desolder the switches and tweak to your liking.
I'm typing this from a Corsair K65 I bought for $40 online, soldered some Kailh Box Navies into, and made my own heavy duty usb cable for out of an existing Goodwill usb cable and some restore rubber hose, etc. Total investment must have been well under $100, and it is built like a tank.
I have found used, 100% functional boards online for much less than $40 as well. I just wasn't too interested in pimping out some plastic Rosewill board. lol