What is the value of a 1997 Liberty one cent piece?
A 1997 US one cent piece? is a Lincoln cent and only face value.
Value of 3 cent piece?
It depends on the date, condition and the type. There were two main styles of three cent pieces, there was the 3 cent silver which was tiny and the 3 cent nickel which was large (the 3 cent silver had a star on the obverse, the 3 cent nickel had a head of Liberty on the obverse). Without knowing the date or at least the type, it is impossible to answer your question.
How much are US liberty 50 cent pieces worth?
You really need to be a lot more specific. There is no such thing as a "liberty" 50 cent piece, rather, there are various types of 50 cent pieces featuring a personification of liberty such as the Walking Liberty, Barber, Seated Liberty, Capped Bust, Draped Bust, etc. You need to post a date and an estimate of condition.