It wouldn't cost that much, but the empeg wasn't designed to drive headphones - which is why it doesn't. Headphone outputs aren't exactly common on car head units.

Mk1 players can be wired to drive headphones internally - there's an audio amp which used to do the 4x line outs which isn't used now there's the burr-brown output drivers. These will drive a 32 ohm load just fine and should give decent volume on headphones - but obviously opening the case, drilling a headphone jack hole and wiring it up *will* invalidate your warranty ;)

Hugo