Those are the prices listed on AllEars as of 2/11. However, we would be there on 11/30 (the week after Thanksgiving). Would holiday pricing be in effect or do these look accurate?
Unfortunately, that page doesn't have prices on it. (The "15-35.99" just tells us what category the restaurant is in. A buffet that costs $22.99 would be listed the same way. )
To the best of my knowledge, the prices you saw are still correct. To be sure that your date is not in the holiday pricing time, calling Disney Dining will let you be sure. Depending on the CM you speak to, they may quote you the range above, which doesn't help, but you can ask for the specific price for your date.
It's odd that they seem to have stopped publishing the dates for which holiday pricing is in effect, but if you ask for the price for a specific date, they can look it up.
Both allearsnet and wdwmagic.com show this price, so it's probably still correct. wdwmagic has a date of Oct 24, 2011 on their menu for Ohana. I don't believe either of them have added in the 6.5% tax rate.
If you really want to be sure, you can call Disney Dining and they will give you the exact price for your dates.