It wasn't me who got the 1st one for 99p!
I'd noticed the numbering scratched off the component, which made me suspicious, so didn't go for that one. Likewise the ones sealed in potting compound - I'd rather see what I'm getting.
The one with the meter seemed to be well made from the picture, so in the end I decided to go for that one, as I felt that a meter would be a useful bonus - it can show you voltage in or out, so I can use it to see the charge of the car battery, and to check things are ok for the Raspberry pi.
I like the idea that it's variable voltage, I've read (and encountered myself) some problems with Pis crashing because the USB power supplies aren't quite up to it, and there can be a bit of a voltage drop along the power lead and across the PI itself.
So I can measure the voltage on the PI board and adjust until I get exactly 5 volts there, not 5 volts out of the PSU.
Brief anxiety when
Burakkucat pointed out it's rated 2A - I'd wrongly thought it was rated 3A like the others.
However, I can't see my current consumption being that high. A 1 Amp PSU is recommended for a Model B Raspberry Pi, and this page here
http://elinux.org/RPi_Performance#Power suggests I won't see anything near 1 Amp consumption - peak being 750mA during 1080P video playback, which it won't be doing. Once running I don't expect to have a keyboard, mouse or monitor plugged in either.
I can't find anything on the consumption of the webcam, but as it's USB it ought not to be over 500mA, and in reality surely should be significantly lower than that.
Having had a think about it, I probably won't even need the extra USB hub - the model B has 2 x USB ports as well as Ethernet, and whilst I might need 3 ports whilst tinkering (cam, keyboard, mouse) I'll need only the camera when it's all running.
I really can't envisage the whole setup needing more than 1 Amp, so the 2 Amp DC to DC converter I've now ordered should be fine for it.
The same seller on ebay
http://www.ebay.co.uk/sch/work4best/m.html?item=271131377887&pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3f20b080df&rt=nc&_trksid=p2047675.l2562 has lots of interesting modules and LED related stuff - a 42 LED lamp module that works off 12 Volts, designed for car or caravan would suit my shed rather well for intermittent use, powered by the solar charged battery. £3.67 ! Bargain.
http://www.ebay.co.uk/itm/42LED-DC-12V-Car-Vehicle-Dome-Roof-Ceiling-Interior-Light-Lamp-White-Silver-WST-/390559960664?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5aef300e58Ian