Yeah I'm looking for how to find as well but I'm looking for sub 100 dollar pieces..lol
This seller consistently puts pieces up for auction.
https://www.instagram.com/its.ania.rose/?hl=en
They typically end in the sub 100 dollar range. You can also request a custom but it will be a bit pricier I think.
The dude I ordered my uv rig from is also pretty cheap. He originally gave me a quote of 90 for a uv accented rig, but I wanted most all of it made of uv so I paid a bit more. I've seen him do auctions, but it's rare. Here is his page.
https://www.instagram.com/broughttoyoubybroadway/?hl=en
When I met him, I had seen an auction of his and wanted to pay 65 dollars for a cfl rig. I believe that's what the auction ended at but I didn't bid, someone else got it. But then I got my uv rig from him. Tell him your price range and see if he'll work with that.
Hope this helps.
Also, search for the tags glassauction, glassauctions on instagram and they will pop up. Follow the sellers you see because they don't always use those tags. It's a very fragmented market.
edit: just saw, she doesn't do customs. Just auctions. Also the quality of her work was better when I first saw her page. She consistently had heady colored rigs. Her latest ones seem less heady. Request she do heady auctions again if you like her previous work on the page.