It will take a lot more money than that to beat the SQ of a fully charged battery. But those Chinese linear power supplies are not that bad. I have been using one.
But if you do not mind the complicated looks, then a laboratory power supply is worth considering. Such as http://www.ebay.co.uk/itm/220V-DC-Di...4AAOSwvzRXx~jt
I use one of those most of the time, set at 15V. They tend to have noise figures of 3mV or less, which surpasses any of the regular Chinese PSU discussed in this thread and others, but are about the same price!! Only the LDO (lurcher) and Mark Grant linear power supplies beat that 3mV noise level. For the cautious user who knows how to set the voltage level on the front panel, it is an option thinking about. I use my modified Capella at exactly 16V with my laboratory PSU.