Generally, I would guess conferring with the client on the facts, briefing, preparing for a hearing, and arguing a hearing would be north of, at least, 25k, assuming a lower-end rate estimate in the $800+ range and a lower-end work estimate of 30+ hours. If I had to bet, I'd go higher than the low-end estimate: both the rate and hours could be close to double. That said, the attorney / firm could be donating the time on this one.
Generally, I would guess conferring with the client on the facts, briefing, preparing for a hearing, and arguing a hearing would be north of, at least, 25k, assuming a lower-end rate estimate in the $800+ range and a lower-end work estimate of 30+ hours. If I had to bet, I'd go higher than the low-end estimate: both the rate and hours could be close to double. That said, the attorney / firm could be donating the time on this one.