99 Buick - Code P0306 - Service Engine Soon

Update: I'm taking it to a dealership for help; to bad I couldn't find any advise here.
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99 Buick Century, 60,000Mi. Service Engine Soon Light Came on.
Car failed inspection with code P0306.
Went to mechanic for diagnostics, three cylendars show high rate of misfire and wires show power traces from arcing.
Replaced Plugs, Wires, PCV - No Change
Went to second mechanic for diagnostics, three cylendars missing but all indicate miss counts, but three show very high misfire counts.
Replaced Ignition Control Module - No Change
Replaced 3 Innition Coil Packs - No Change
Went to third mechanic:
Computer indicates all cylendars have a low miss count but 3 have a very high miss count.
Driving the car.
Starting out slow it shakes from the missfires until about 30mph then smooths out.
Driving at 30mph and floor-it into passing gear and car runs very good with strong acceleration, no misfire.
Drive a 25 and ease up to 30, car misses continuously.
Drive at 55 and you realy can't tell there is a problem; runs smooth.
Fuel consumption has doubled.
Some strong fuel smells when car first starts up.
Rough idle.
Two mechanics have declined working on car after hearing what I've already replaced. They say I need dealership with Tech 1 computer.
One mechanic said this is common problem with 99 buick 3.1 cars.
I was a mechanic for 10yrs, between 1968-1978 so I am not afraid to replace parts and would rather try replacing a few sensors before letting a dealership take my first born and the shirt of my back.

Lets add up all your parts thet you already spent the money on! Add it up go ahead. Now take it to the dealer and I bet you spend less than half to fix it right the first time.

I guess you never gave a thought to the fuel system as your cause! I would guess a bad injector would cause a miss. But you rather spend 400 dollars on throwing parts instead of spending 60 to 80 dollars on a dealership to properly find the problem.

Do you know why those 2 mechanics ( Your term not mine) (my term would be parts changers) declined taking a look> Its because they ran out of parts to try!

Your right; but I figured the dealership will hit me for a minimum $1,000.00, probabally closer to $1500, so I thought it was worth a try.