Does anyone have experience with MOTH tonearms? I see that the MOTH 1000 (supposedely a RB1000) is approx 800USD less than a RB1000 - are they identtical except for the 'logo'? How can this (price difference) be?

Here are a couple of links that tell the difference and offer everything you ever wanted to know about these arms:
For a long time I used nothing but Rega arms for my table sales, but a couple of years ago I "took a chance" on a Moth arm. I noticed no difference in either build quality or sonic performance. After that, I switched to just OEM arms and have never looked back.

The only downside I can see is the erroneous perception "out there" that they are somehow inferior. Hopefully threads like this will dispel that perception.

I import the Moth arms from the UK and most of the models are exactly the same except for the logo. The only one which is slightly different is the Moth Arm2 which is very similar to the RB301 except is retains the older style ant-skate device as found on the original RB300. Rega actually make all of these arms at the same factory in the UK and sell a number of their products to over 15 different companies worldwide. OEM arms usually come in bulk packs of 5 which helps to save on cost and OEM companies generally do not spend a load of cash on adverts. So with the cash you save on a logo buy more records! Long live vinyl.