'04 Aveo Hatch - blown head gasket - drive until it dies or sell now?

[Daox]

If the headgasket is bad its probably running noticably worse than before. If it isn't running bad just bring it to an autoparts store and have the codes read and tell us what the codes are.

[Rob D]

Here are some notes from my sister's mechanic:
SOME CODES: DCTs, PO3OO, PO700, P1781
ENGINE MISFIRE(A VALVE SEALING CONCERN) It's sluggish on hills and highways

Here is the info:
(NEEDED)
HEAD GASKET SET
VALVE COVER GASKET
INTAKE VALVES
EXHAUST VALVES
VALVE SEALS
(SOME OTHER COSTS)
SPARK PLUGS
REMOVE CYL HEAD TO REPLACE ALL VALVES AND SEAL
DIAGNOSE ENGINE WITH SCAN TOOL
MACHINE SHOP LABOR(DONE IN AN OUTSIDE SHOP) $1,000