Is this worth the $$$?

I can´t believe the prices they charge for these if you see whats in them.

http://vec.mine.nu/modules.php?set_albumName=album44&op=modload&name=gallery&file=index&include=view_album.php

All it is is a rheostat attenuator in a metal box.

So seeing this is there really any difference between this and something like the Shure XLR to Mini convertor with Attenuator for $40 ? (other than the mixing of 2 Mics

The BeachTek type boxes give a secure connection to the camera or belt (Studio1 type). Most of them, but not all, use transformers to maintain a balanced connection as far as possible.
They also give the ability to attenuate the signal either in small steps or continuously.
They can either mix or keep separate the two main inputs.
They allow for using line-level or mic-level signals, as well as aux mini-plug inputs.
They can select different grounding schemes for eliminating ground loop hums.
The better models from BeachTek supply phantom power and/or extra gain control.
The Canon MA100 and MA200 often pick up electrical interference from the required power connection to the camera. They also don't allow for use of line-level signals, mixing of two inputs or doubling a single input.
The Shure adapter works well for a single mic, but requires that it be secured properly and doesn't have any controls for flexibility.

If'n you want to save money and feel you could make a similar product go for it. (These aren't Radio Shack parts) I've been in related tech fields for over 40 years and I wouldn't waste my time. There was a time when I had a metal shop at my disposal and carte blanch on parts but that was 30 years ago and in the military.

The unit is very well engineered, has excellence balance , mounts to the camara and it looks good.

i've used nothing but a 1/8 stereo to XLR adapter cable and had no problems abd i also own a DXA4, DXA8, DXA10, Sound Devices mix pre and a Sound Devices 302.

There will always be those that feel that it takes nothing to build such a unit until they actually try. Some people are also more easily pleased than others.

I felt the same about these mixing boxes, and did a little research as I was sure I could build my own. Was very surprised at the cost of the transformers. Therein lies the "secret" to the quality.

The transformers are the costly item ($100 ea is not unreasonable for quality units that cover the frequency range). Thereafter it is just a few components soldered together in a box that fits - and fits well.

Im not saying its not a quality product, but the inside doesn´t really look professional.

The casings are made by Hammond http://www.hammondmfg.com/dwg.htm

I can understand your reaction, but you also have to remember that BeachTek does not build and sell in mass quantities. It's a specialty market. So they have to recover their costs and make a profit from relatively small sales volumes. That's why everything is so expensive in this field. The convenience and "fitness for use" is what we pay for. The inside of the Beach may not be pretty, but the design has stood the test of time for a lot of users under a lot of circumstances.