You want optical quality, ease of use, and aperature - in that order. I doubt you will find anything new that satisfies all these needs for less than $30 new. Try ebay, some very nice zeiss and bushnell's [two of my favorites] are often listed there. You will not be disapointed with either.
Some decent 10x50s are usually easy to find. Watch out for the exit pupil though, some of them are bizarrely over-sized.
Ocean Pacific carries lots of binoculars in the $30 and under price range. I bought a pair of the 10x50s to keep in my Subaru for quick looks. I don't want to leave my Nikons in a vehicle unattended, but a pair of $25 binos...OK. BTW, the quality is much better than you might expect for the price point.