I've got 4 free ticket vouchers that expire August. (NO ! I am not trying to sell them !) I've only got one upcoming trip planned that I could use them and that is SEA -> ORD. However I'd really like a bonus trip from SEA -> LIH. The vouchers aren't good for LIH and the fares from SEA - LIH are $600 - $700. But I see that sometimes fares from California (SJC, SMF, etc) are much more reasonable and my thought was to use the voucher to fly from SEA to California and then use a paid fare from there to LIH. The fares to California are in the $200 range.

So is there a general rule about the value of these vouchers ? Is is much more $200 ? Would I be better off holding onto the voucher for my trip to ORD and paying the whole way for my trip to LIH ?