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.
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.