Did you ever want a phone that is not just a simple one? You might dream of HTC, Motorola, Samsung, Sony Ericsson or even Iphone. You may want a 1 Ghz processor, or maybe you want a dual core, who knows? You might dream of some HD video camera on that phone and maybe some cool effects.
Before buying one, you should first check forums for common issues. If the price of your desired phone lowers very much than you should not be thankful, but cautious. Probably there is a strong reason and it's not because the producers wants everyone to buy it. My guess would be that the phone has some serious problems and you can be 7 in 10 people who can experience it.
I am writing this, because well I heart about 2 phones in particular that have some serious problems. One of them is Sony Ericsson Vivaz which I heard makes calls by himself and there is no locking screen when you have a conversation. But that you will have to figure for yourself, I didn't have the phone, so I can't actually say it's a bad product.
The second phone is HTC Desire S, which I personally bought, and after two months of using my motherboard crashed. I was downloading a few programs at the same time, and it froze a few times, I removed the battery, and it never started again. One thing will be that you should never remove the battery. Another thing is that you're the risk to have this phone in service a lot of times. Other users experienced the same problems.
It's your choice. Maybe your new phone will work excellent, but I guess you'll need some luck for that.