Also, although this may not help you now, keep in mind for the future that you can check availability in fare buckets before you purchase... you can do this on united.com or on seatcounter.com. There is an entry in the FAQ (stickied at the top of this forum) with instructions on how to check availability on either site.

If you check before purchasing, you are much more likely to find flights that have sufficient availability in the buckets you need. Sorry it didn't work out this time, but hopefully it will help in the future...

Note that cheaper seats may be released - someone with a cheap seat might cancel, for example. However, there's absolutely no way to know this, as the previous poster mentioned. If you buy now and the fare drops, you can always refare to get the difference as a Type B voucher. If you wait, you may run the risk of losing even the H fare, depending on availability.

Good luck...