How hard is it to do a head gasket job besides time consuming?

As long as you have the right tools, especially a torque wrench, new head bolts, no problem. If the gasket blew, it is recommended that you have the head checked, and decked if needed prior to reassembly.

Make sure you label everything before you take anything apart. Both sides of electrical connectors, vacuum lines and connectors, coolant hoses, etc. This will (should) preclude connecting anything wrong.

Take pictures. Write a list of everything you've labelled and check them off as they are reconnected/reassembled.

That depends on how much they need to take off. Call around to local machine shops and find the best rate. When I've had to do this for my cars, I've been lucky and worked at a shop with the proper machine tools to do this and thus didn't have to pay for it.