Head Gasket Question

I don't mean to start another head gasket thread, I know there are many threads and comments here already, but my question is a little different and I didn't want to sidetrack and current discussions.
My 2010 Prius at 271k miles, started the engine shake at acceleration from idle and put up the #1 cylinder misfire code, with my coolant about 1/4 inch low. The car has been running perfect until now.
Obviously it needs a head gasket and EGR cleaning. My local mechanic suggested getting a new car and gave me a ballpark estimate of around $3500, or more if it needs a new head, without looking at it.
My issue is, I just put in a new Hybrid battery in October! Yeah looking back, that was probably a dumb decision. But I had always assumed oil burning would be the demise of this car, and since it doesn't burn a drop of oil, I figured the engine was good to go 400-500k. I also have the Prius Offroad lift with heavy duty springs and larger tires, so I don't want to junk the car.
My question is, is there a preferred Maryland mechanic that does Prius head gasket jobs for a lower rate? I believe I can still drive the car to a location. Is it worth fixing? If not, could I even sell it with a bad head gasket?
This all happened unexpectedly. I've always done my own oil changes and have always been amazed that it never burned any (I check it almost obsessively, always expecting the dreaded problem I read so much about), so I figured the car was worth putting money into, such as the batteries, shocks, lift, etc... and now this.
PS. It's my only car, daily driver, so I'm forced to make a decision. I can't just "park it out back" until something comes up.
Thanks for any suggestions!

 

To Tom, yeah mine has the JBL and solar roof, too! To Max, yes, that is correct (I bought it used with 86k miles 7 years ago). Everyone said it would burn oil and mine never has, even to this day, and mine has run perfectly through all kinds of use, so I figured I just got a good one, or it was an issue that affected more cars than normal, but not every one. Obviously I was mistaken.

 

Mendel, yes, everything is exactly as I described. I had read the threads on here for a few years and and was always worried about the oil burning problem. I checked my oil constantly and always changed it when the light came on. Even now, it's exactly at the full mark, just as when I had changed it. I also always looked at my coolant tank and it was always in exactly the same spot. Since I seemed to have no problems, I figured my car missed being affected by those problems somehow. I bought the car used with 87k miles some years ago, and with it came some oil change and tire replacement receipts, but no other major work. I've driven it the rest of those 271k miles and never did any intake or EGR work on it at all. It always drove perfectly fine like the day I got it. I was hesitant about putting a new battery in it a few months ago, but I figured if nothing has gone wrong by now, it probably wouldn't. Haha on me, I was sure wrong about that!

 

b
Thanks for your suggestion. My initial thought was to get it fixed, too. I walked in to my mechanic and told him my situation, and he talked me out of dumping 4k, possibly more, into a car that old and with that many miles. He's probably right. It's just hard for me to try to get something new after just putting a 2k battery in it (plus all the other stuff that has more or less recently been done like brakes, sway bar, small battery, shocks & struts, and the lift & tires).
I don't know, I'm torn over this. Obviously, if I get get him or someone else to replace the head gasket, I'd have them clean the intake and EGR system, and add a catch can. That would send his price over 4k. That's pretty steep. I was hoping there were members here who know of an "enthusiast" prius mechanic who is familiar with the job and knows all the Prius-specific EGR/intake issues, and also could do it for less hours (mine estimated 10 or 12 hours, I think).
And BTW, I don't know your situation or history, but in case you haven't already, please take your car the get the whole EGR system and intake cleaned! (or do it yourself if you can). Everyone recommends adding an oil catch can, also. Take it from my experience, it can be running fine until one day it starts shaking, then it's too late! I wish I had taken the advice of the members here...