Prices - check the actual sales on ebay, that should give you an idea. But it depends a lot on condition, area, make etc.
Most of the new saxes come from China and Taiwan now. Variable quality, hopefully you can trust your local dealer. Good to buy from them, means you have local support/advice/service. But it puts the price up a bit. YTS23s have a good reputation, just depends on how much it's been played/serviced. Ask around, see if the local guy has a good repuation or not.