$1200! For a nimh battery. Bit excessive really.
It isn't for a nimh battery, it is for a low noise high resolution power supply with optically isolated controls and a pair of battery packs with a switching and charging circuit.
The way this thing works is that there are two batteries. At any given time, one is charging and the other is powering the circuit. When one battery is drained, some relays flip and the live battery is switched in to power the circuit while the dead battery starts charging. The result is that you have a battery powered floating power supply that never runs out of juice. They also claim that they reduce the switching transients to nearly nothing, but I don't know how they do that.
This is tied to the SRS 'SIM' rack, but that is good for its designed application. The purpose of this supply is to provide bias voltages for floating sensors or to power a small sensor preamp. In any case, the signal would then be sent to a non-floating amplifier built into the SIM rack.
Sure, the parts cost is still only a small fraction of the sale price, but compared to paying someone to build an equivalent product the price is cheap, and I don't even know of any competitive product on the market.
SRS makes great products, and they are really reasonably priced if you compare to people like agilent. They were really leaders in low noise digitally controlled electronics. Their instruments have good low noise analog design, and their digital components are very well isolated from the analog side. A technique they use in some of their preamps is actually to stop the clock on the microcontroller except when you press a button or send a serial command, to completely eliminate the possibility of digital noise creeping into your analog signal path.
Their main drawback is that they rarely update their designs. A lot of their DSP instruments like their digital lock-in amplifier and spectrum analyzer are still using DSPs from the early 90s, and several of their instruments ship with floppy drives. This is good in terms of having a lot of confidence that the device you buy today will work as well as the device you bought 10 years ago, but definitely they also suffer limitations due to the products available at the time. A lot of their analog frontends use monolithic matched jfets that are easy to blow out and hard to replace.