if you cannot do the work yourself, It won't be worth it. More than likely, bent valves... soooo this means, pull engine, pull heads, new valves, grind valve seats, resurface heads, timing component set, head gasket set, assemble and reinstall engine. chaa ching. Cheapest shop I know that will do it in my area gets $1600 plus tax. Most get 2K If you have a friend into Subaru, he could throw an old timing belt on and do a compression test to see if you bent valves.