Here is a very cool looking clock kit built into a Ice Tube I came across yesterday web surfing.
This kit is available from the Make store on sale for twenty dollars off at $65.00.
Velleman also offers a digital clock kit but not as sharp looking.
But with a price under $30.00 this might fit your budget.
This last digital clock kit I built was a Heathkit, must have been around 12-13 years old and it worked!
Might be time to build another just for the fun of it.