spark plug wires: old but under 10kOhms

Hi,

I just check the spark plug wires on my newly purchased 1997 Civic:
they are from 1997, probably the OEM wires, and they all measured under
10kOhms. I will also look tonight with the engine running to see if I
notice any "sparks" around the wires, but I was wondering if I should
replace those anyway. I am trying to make small (read cheap!)
maintenace jobs, such as replacing the air filter, spark plugs, maybe
the rotor and the cap, and all these are under $20, however the spark
plug wire set is $47. If it is not absolutely necessary, I wouldn't
replace them.

What od you guys think?

thanks