Hard to beat a mini Griptilian, especially an RSK. What exactly is your reservation about the RSK? Is it that the design is 4 years old or that the specific knife you are considering has been used for 4 years? In that case, make sure it is in good condition and pay less than ratail and you should be fine.
If you want a new knife, you could just buy a new RSK, but if you are looking to spend less than the cost for a new RSK, other good-value knives that are similar are the mini Griptilian 556 which is very similar to, but less expensive than the RSK and the Spyderco Native which has the S30V blade steel, available at Walmart for $40, both made in the US. The Spyderco Delica is also a great knife and good value in that size and there are many others as well.
