Vintage Synth Repair

I realise this is a fairly wide-open question, but hopefully some people 
will be happy to share their thoughts...

I'd like to buy a reasonable 'beginner' benchtop power supply, for work 
up to around 30V and 5A, preferably dual output if at all possible.  I 
would like the usual bells and whistles like constant voltage, constant 
current and adjustable current control.  I don't want the cheap rubbish 
but I'm only looking for the next level up; I don't need a 
top-of-the-range unit.  I'm hoping to pay around $300 and I'm located in 
Australia so locally available brands would be great too.

Is this in the ballpark?  What models do you recommend?  Any 
makes/models I should definitely avoid?

There are a lot of older units that come up in auctions regularly - are 
there any models I should be on the lookout for, and if so what sort of 
price is reasonable for a second-hand one?

Thanks,
A.