The prices in singapore are a bit different, so I cant comment on the price itself. Although it doesnt sound excessively cheap. Rule of thumb, as long as its been used, cut the price by half. Then bargain till the seller is pissed off
I bought my Halcyon Eclipse 30lbs BCD at US$410 when the cheapest any dive shop in Singapore was selling it was at US$830. The BCD was used for 1 weekend trip and had 5 dives on it. I could verify this fact. I was on the trip with the guy when he had bought it brand new from the shop I was working in.
Anyway, do remember to take a good look at the following :
BCD :
1. General condition : scratches, faded material, stiff material, cracking corrugated hose things like this. They'll give you an indication of how old the bcd actually is. Any BCD with less than 50 dives should look identical to a brand new BCD.
2. Check the power inflator. Inflate, deflate the BCD a few times to check that this is working.
3. Check the dump valves (these are the circular valves usually 2 of them on most BCDs, one near the top left hand corner and one at the bottom left hand corner.) Check to see that they aren't leaking and they are dumping air fine. Also unscrew them and check the condition of the spring and the rubber diaphragm inside for wear and tear.
4. Most important. Get a tank, FULLY inflate the BCD till its max. You'll know its at its max when the dump valves automatically start farting out air when you try to pump it in. Leave the BCD fully inflated in the corner for a while like half an hour to an hour. At the end of it, the BCD should still be as hard as it was when you first put it there. If it isn't, its leaking air.
Reg checks :
1. General condition, especially of the hoses as these usually dry up and crack.
2. Breathe from it when its NOT hooked up to a tank. You should not be able to inhale at all. If you can inhale, it suggests there is a problem.
3. Breathe from it when it IS hooked up to a tank. If there is a slight braaap sound when you exhale, its ok. Thats cos the diaphragm in the second stage is not wet.
4. Hook it up to a tank, pressurize the system and listen for leaks. You'll be able to hear any major leaks. Even better, throw the whole thing in a tub and look for bubbles.
5. After pressurising the system to 200 bar with a full tank, turn off the tank valve but do NOT depressurize the system (ie dont press the purge!) and leave the system fully pressurized with the tank valve turned off in a corner for at least an hour. When you get back, the SPG should still be reading 200bar (it should not have dropped)
6. Unscrew the second stage and generally check the condition of the parts inside esp the diaphragm. Take a peek inside the first stage (look at the filter) all these will give you an indication of how the reg has been used by its previous owner and what condition it is in and if the bastard is trying to pull a fast one on you.
I hope this helps!
and get a real deal or buy new....... Your not saving enough right now, my $ .03
