Check the back plate number...if it's 289 or higher (and should also be the same size as the front plate number), then that note could very well be worth more than the $1. If it's smaller and 288 or lower then it's still worth a little more than a CA or DA block note, but not by much and definitely not worth near as much as the $1.
Sure its worth more than $1 -- Its a $2 note! (sorry, I couldn't resist the comment) Aren't the BA blocks on 1928D mules are worth about 2.5 times more than other blocks?
Yes....right around that. The standard guide to small size paper money has the CA block at $15 and the BA at $50 for the mules in VF condition. The non-mule BA block however is listed at $1000 in VF.