I agree. I would locate guys like Big Forest Frameworks already more in the expensive boutique sector.
My frame is built by Jacek Orlowski in Sczeczin, Poland. He used to have his workshop in the velodrome and built frames for Poland's national track team when they were still riding on steel frames. So yes, long time ago.
My frameset is made of Columbus Life throughout and I got to decide everything. It is fillet brazed which is considerably more work to do than just welding it (like the Standert frames). I paid around 1200 EUR including paint on frame and fork. So that's a lot cheaper than what Standert is asking for their better steel options.
I can also recommend Antonio Taverna in Padua, Italy. You can find him under his "brand name"
https://www.vetta.it/.
His quote was roughly the same as Orlowski's but I went with Jacek as he's closer to me and I picked the frame up.
Especially in Italy, there's lots of these smaller and lesser known builders still around and they're asking very reasonable prices. TBH at this point I'd always go custom, if I was going for a new steel frame again.