Your friend is probably correct. It’s a well known problem with those engines and the fix is expensive. Besides the usual head gasket procedures, removing the heads involves dropping the engine cradle and retapping and installing special inserts in the block.
And because it’s so widely known, resale value is in the pits and even some scrap yards aren’t taking them.
It’s a real shame because otherwise these were very nice cars but if you can find a reasonably priced independent mechanic who’s experienced with this fix and hold onto it long term, accepting that it still will have no resale value, it may be worthwhile.