Many years ago, I really wanted a Rover SD1. There were loads of them in the classifieds from about £300. I nearly bought a 2.6 Vanden Plas, and put a deposit on it, but there was damp in the boot, and the interior didn't seem to be the correct one for the VdP. It had had a load of owners, and the young guy who owned it was a kn*b, so I didn't go through with it. I couldn't rely on an SD1 as my main car, as I was renting, and had nowhere to store it as a second car. Years later, and when I went to look for SD1s again, there were very few available, and certainly none for less than about £2000 - most really good ones were going for £5000!!! Now they go for even more than that!!!
Before buying my 9-3 Aero, I was actually after a Rover 820 Vitesse coupe. I had seen some around for about £1000, and then one came up on Ebay with a starting price of £1100, but it was clearly a good example, well looked after and in excellent condition. I put a bid in, but someone had bid higher, and so I bid again, and again....going beyond my max of £1500. It kept on going up, and I got to my next 'max' of £1800, and as I hit the bid button, the price increased to over £1900 - at that point I bailed. The car went for just shy of £2000. When I look for them now, I struggle to find one for less than about £2500, and they are often more than that!!
I was so gutted that I didn't get it, and I was all fired up to buy something, I started looking at what else I'd like. Initially Saab 9-5s, as I still missed my original V reg one from many years before. Whilst looking, I broadened the search to 9-3ss, and found they were in my affordability bracket

I was looking nationally for a while at Autotrader/Ebay/Gumtree, before finally finding the one I bought, locally!!! Got it for £1250, when others were going for £1500 - £2000 - Now I see some going for £500 - £600, so they are probably nearing their low price point, which suggests to me that now is the time to pick up the bargains.
I was horrified to see people on the Saab 9-3 Facebook groups stripping perfectly good 9-3s for spares, rather than selling them on to someone who would get them running again. Some of the excuses for stripping them were very poor, but it means there should be plenty of spares around, and of course as they shrink the 9-3 population, those left should start to appreciate in value......