Thanks for everyone's input.
I do have a Rancilio Rocky that seems to be a good grinder. Any reason to upgrade that?
I have considered a used machine, but have no experience in repairing or maintaining an expresso machine so I have to wonder if that would be a good choice.
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The Rocky is considered by many to be an expensive minimum starting grinder. If it was me - as in my 2¢ - I'd consider cleaning it up, selling it on eBay, and using the proceeds to buy a used commercial grinder & new burrs.
I always tell folks that if you can read a road map & have fair-to-middling cognitive skills, refurbing the used HX machine is pretty easy. My wisest bit of advice though - take lots of pictures as you're disassembling the machine. They'll be invaluable when you begin reassembling the thing.
We've just started a HX User's Group on Yahoo, modeled after the Gaggia & BUG-Is-Bunn User's group forums. We're hoping to get copies of parts diagrams & user's manuals for the different machines. We already have some very good technical expertise on board, ready to help the noob who gets lost.
If this is over your head then I suggest a
Gaggia Classic. They're a bit more expensive, but they're great machines and will last for decades with just a bit of preventive maintenance.
PID installs (whether you put the parts together or buy a kit) are for someone with a track record of DIY projects. They're not difficult to do but you will be working with 120 volts and boiling water & steam. If you're not comfortable with that I suggest getting someone else PID your machine for you.