Well finding pure MDMA can be problematic but it's certainly not an insurmountable problem if you take your time and research it well. While it's true that there is a fair amount of "cut" product and even fake product on the market the DEA's own statistics do show that a large and growing percentage of seized "ecstasy" is testing pure, so statistically speaking you're more likely to find pure MDMA on the black market today than at any time in the past. With that said you do have to be careful. There are ways to rule out the presence of certain contaminants such as methamphetamine, you might try purchasing a kit which provides certain chemicals that test for the presence of methamphetamine and other contaminants:

http://www.raveready.com/MDMA-Ecstasy-Testing-Kit-p/dansacc....

(I'm not vouching for the above kit in particular, do your own research in this area)

If you feel like you need a third party to be there with you then maybe you do, each person is different. I will say that MDMA isn't like a psychedelic where you definitely want to have a "trip sitter" present, it's a much more controllable experience.

In my opinion MDMA may feel mystical, magical or sublime; but it doesn't feel weird. MDMA "provides a centering experience, rather than an ego diffusing experience" (Dr. Philip Wolfson).

If you decide to go ahead without one then let me advise you to try it outdoors in private setting, perhaps near a lake, or a mountain top, somewhere with a view where you can roam about enjoy yourself. If you have a significant other then I highly recommend taking it together. This drug is perfect for couples therapy.