sorry to hear the situation your in.
First off bottom end is a must, when the gasket goes water gets into the cylinder, water is none compressible so means the piston can't move up enough and subsequently pinches the bearing between the rod and crank.
Problem you have is cheap means your prob gonna end up paying twice.
3k for engine rebuild is about right sort of ball park, being very specific with what is and isn't included. Also the exact extent of the damage wont be known till its fully stripped down and you get a full engineering report.
Clinic are currently building my engine ( http://uk.subaruownersclub.com/forums/topic/15071-tidgys-project-type-r/ ) and there were various things that simply can't be costed until you know what's needed. Mine needed a block, heads needed the valve guides redoing which both add to the bill considerably, but better that than use a block that is way outside of tolerance due to taper on the bore or heads that the valves aren't guided properly.
Come service/maintenance time your not paying costs for what the car cost you, but for what it was new. While it may have cos under 8k for the car, new it would have been near 30k. People forget that when they buy them.
Scoobyclinic do all my work and you could always pop in and discuss options with them.