1995 LS400 super low compression

[Sir Coolant]

So I'm on Facebook Market place looking at this 1995 LS400. Car looks amazing but has  super low compression. He said it's cylinder 1 and it has 30psi. At first when he told me low compression I was amusing its at least in the triple digits. Could it be worn piston rings? I was going to go do a tune up on if I do get it. Spark plugs+spark plug wires, distributor and to double check the valves to see if they need to be adjusted/replace. But since he said compression is 30 psi I'm thinking it's piston related instead of valves. I'm doing a trade for it. So I'm not at a total loss if it needs a new engine. Just wanting other peoples opinions on this problem. 

[RX400h]

Here is a good general guideline for low cylinder compression:

8 Causes Of Low Compression In A Car Engine (& How To Fix) (mechanicbase.com)