Of course. That's how it goes:
1. you buy chips on that groupbuy with burnin as assembly service
2. on a webpage burnin will set up in a few days (or a week) you order assembly service (DIY kit or complete miner), that's when you pay to burnin
3. when chips arrive, SebastianJu will send them to burnin
4. burnin assembles the boards and sends them to you

EDIT: there is that same groupbuy thread in english: https://bitcointalk.org/index.php?topic=187660.0