Expensive tools you regret selling

Back when I was into Jeeps/4x4s I bought a JD2 bender/dies and tube notcher. When I got out of 4x4s I sold the tooling.

Regrets.

None.  Never sell tools (unless you're upgrading)... 

What? People actually sell tools?  

This is a foreign concept to me... 

Like guns, don't sell tools.

Like guns, I hope my wife sells them for what I paid for them not what I told her I paid for them.

Sell(?) tools...
That's a phrase I've never heard

Tools stay until they are broken, then are kept around for parts, then maybe after a decade of being broken, get tossed into the scrap pile.

Nothing I've regretted because I have had copies upon copies.

I sold a powered hack saw about 10 years ago, I regret it all the time. 

Eckold Piccolo sheet metal forming machine , 

Wish I never sold it and  now too expensive to buy again :(

For 25 years I joked I had tools (SU Carb Rebuild Tool Kit) for cars I didn't even own and now I own a 240Z needing this someday. 

Never sell tools.  Does the wife ever discard or sell kitchen utensils?  (No)

I do sell some tools that I'm either sure I won't be using again, like the way cool but rather esoteric Stomski air-cooled Porsche exhaust stud drill-out jig, or that are commodities that take up a lot of space. I've bought and sold cherry pickers and engine stands at least 3 times. Do that used and they cost no more than about 10 bucks per use. Sometimes free.

I did regret a little sending most of my common SAE tools to a friend's mission school after I sold my 'cuda and was sure I wouldn't be wrenching on old American cars.

It's true, I haven't been wrenching on old American cars but I bought a Volvo 122, on which only the Weber carbs are metric. 

All of them.  Almost 2 years ago I moved out of state from an 1800sf house with a 2 car garage and 4 car driveway to an 800sf apartment with 1 parking spot. I sold a lot of my tools because I had no idea how long it would take to find a house and I wasn't going to spend more money than my tools were worth to store them off site indefinitely.  Today, I signed a contract on a house with a carport and detached 2 car garage (with electricity!).  I will rebuild my collection! January (or sooner) I start looking for deals...