Advice: AU11 Futura (LPG)

Gday FF Members,

I have a vested interest in purchasing an AU11 Futura (LPG) upon having a vehicle inspection done I was told that due to it being a dedicated gas vehicle 5 valves had burnt out and that I could expect this problem to occur every 2-4 years or so.

I ask if anyone other members know of or have heard this as being a problem before and whether it's best to get back out on the road and find another car rather than negotiated a cheaper price and have this one repaired. Any help will be much appreciated!!

cheers

PS this forum is excellent!