Yes it is bad news for us Cessna owners in a way... end of 2016 we need to be "SIDS" compliant or the MR runs out. That being said I cannot see how the 7500 odd 100 series aircraft on the register here in Aus can be done in time be the 3000 odd LAMES in the country.........
The expensive part is two fold - if you find corrosion you have to fix it. The other expensive part is all of the mods that you are required to do - tail stiffner, door stiffner, inertia reel on the pilot seat.... Bob - I would get a second opinion as the LAME I use has completed a 210 for just under $60k, a 206 for around $48k and they are far more in depth than a 182 and the 172 is looking like 26-28k so somewhere in the $40k range? Given you still have two or maybe three annuals between now and then the cost can be stretched - although not as far as I was planning.
One tip is talk to your LAME or any LAME who is planning to get the crack testing done on the wing roots and attachment points - the cost of flying these NDT guys in is huge, if you can fly them in to do three, four or ten aircraft it makes it a LOT cheaper for you (albeit at a time you may not anticipate) to do wings and leading edge all in one hit. The LAME just needs to have enough room to have a dozen wings sitting around.........