Back from cooking the evening meal.
I can see this thread will become schizophrenic.
Valuation.
Thanks for the bits of information. One owner=good with full FSH=good, 93k =2/3 of lifespan not bad. (Why previous owner spent a fortune, presumably everything through Audi.) Pictures now help = looks standard spec. Still need answers to my earlier points and to add PDC(Parking Distance Control), rear electric windows (seems to matter but God knows why - I sit in the driver's seat.), space saver sparewheel and false floor?, full original toolkit?, tyre condition? to mention a few more. I have looked at every single advert for a FSI on eBay and gumtree in the last two years and I have no real idea of value, they randomly vary so much but I will venture a figure eventually given the information. Be honest about condition of paintwork. The Colour Storm aspect I discount, very much a marmite thing, probably invented by Audi Sales department to push a sales campaign, I prefer plain livery, each to their own (howls of derision from CS owners) and to my mind adds no value.
Mechanical Problem.
Do you get an engine management light on the dash? How noticeable is the misfire. Have you a scan test result. Are you sure the first garage swapped injectors (between cylinders or new on number 1?). It is not clear if the car was looked at by Audi or it is just a quote to think about. If it is a quote, don't do it. With the time that has passed and the rarity of the model I doubt if their mechanics have any more idea than anybody else and will simply replace with lots of new very very expensive parts and charge an arm and a leg labour rates. You are not that far from WOM ( an A2 specialist who know it inside out), take a day off work, book it in with them, pay reasonable labour rates and job sorted [I have no connection with WOM].
Andy
PS. My instinct was injector number 1, but BoxyA2 got in first. (Great minds think alike and fools seldom differ!!) or wiring fault to the injector, but surely they checked.