I just don't get why they could be so much cheaper than other big brands? Is the quality below par? Or is it just a hit an miss with these kinds of purchases? (i.e. or you get a superb bike, or you get a cracked frame)
In essence, this is why this forum exists.
If you buy from long teng, you buy from a factory that doesnt even have a brand, its marketing budget is zero, and the 268 that i ride is open mould, so it cost them absolutely nothing to develop. They OEM for various brandes, including Argon 18.
At the other extreme, you have pinarello, that is owned by the same conglomerate that owns louis vuitton. They sell a brand, they develop their own designs, they sponsor teams, they test stuff in wind tunnels, and so on.
This forums helps identify where to spend your money, based on what you value. If you buy a yeoleo frame, you pay 1000, you could get the same frame from 500 from someone else who doesnt pay influencers. for example.
If the VB TT023 appeals to you, order with confidence. You will receive a road worthy frame. If you happen to be the 1/100 who receives a bad frame, complain and get your problem fixed. But you can confidently assume you'll receive something safe to ride that will put a smile on your face. I've built 4 VB frames, had zero issues.