The 997.1 must be nearly at the sweet spot now with plenty of decent looking examples about. Nice 996 C4S's are almost the same money as them. Also trying to find a decent manual 996 C4S cab (my poser's dream car) is very tough. If only I had a spare £20k hanging around. Ho hum...
On a side note, passed a lovely black 996 turbo cab on the way home from work. Also hard to find and prices are rising!
Not really a nice 996 C4S examples are around 20k. 997.1's at 20k are high mileage, poor spec of feature the dreaded tiptronic slush box.
Clean, lower mileage examples of 997.1 with good specification (manual) are in the 25-35k region.
In short
996 C2/C4/S
10k = Bottom of market pile of junk
15k = Get a decent example
20k = 996 C4S in excellent condition
20-30k = C4S in perfect condition or 996 Turbo
997.1 C2/C4/S
20k = Bottom of market or very high miles
25k = Nice examples
30k = Low mileage with very driver focused specification
30-40k = Perfect exceptionally clean with top spec and low miles
997.2 C2/C4/S
30k = Bottom of market and very few cars to none or a previous written off/stolen car, AVOID!
35k = Around starting price, some OK examples, tend to be higher mileage.
40k = Better spec, lower mileage etc.
45k = Clear great examples here.
50k+ = Special edition cars, though GTS still over 60k