Dypen,
I've been in the market myself. Things I've noticed or have been told are:
1. That the prices in the US seem pretty consistent. $120k will buy you a very nice aircraft. 182 prices in the UK seemed to have crept up quite a bit since the exchange rate moved back from 2-1 to 1.6-1
2. Prices in Europe are horrible. I presume this is because of the Euro. Some friends of mine in the US a year or two back were cheerfully selling their aircraft in droves to queues of French aviators. Not sure how things are now with the exchange rates.
3. Old aircraft aren't necessarily bad. With new paint, a decent interior and a good engine they will (arguably) outperform newer (heavier) aircraft.
4. The old RGs go about 15 knots faster and the TRs are even better at lifting as the Turbo allows you to get plenty of power on take-off even when hot and high. The older wheels up versions I believe might even perform better than the new fixed turbos from what I recall.
5. Pick an aircraft that has been regularly flown if you can. If it's been sitting in a wet field or a hangar for months, then you run the risk of a spate of bills in the first year. For some reason they do like being used and if they aren't, they end up taking vast amounts of money out your account.
6. The 30 year old beauty I ended up buying is super and is everything I could have hoped for. She performs smack on the POH figures, though she does need EDM data to help achieve this.
7. Ask your engineer and any other engineers you can find. The chaps in the industry know where the lemons and the peaches can be found. 'Ah yes, I know that one....' can save your life. (and DON'T FORGET to get a full survey by the way)
8. There has been a dearth of 182s on the 2nd hand market over the last 12-18 months, but some are now appearing in the magazine ads and webvendors. If you find a good one. Move quickly!
9. Oh and for price, obviously haggle. You should get a bit off the asking price, but in my experience people don't move that much - maybe 5-8%.