I can vouch for old mate here, i been buying him for yonks now, he doesnt screw around and everything is done at the best rate, all realtime transactions with him aswell, and upfront personal communication on several platforms, if your worried start small but it is all good with this dude, you wont have any problems and you shouldn't stress if there is any hiccups, this guy takes care of his buyers.

Edit, more than once, if he didnt have the entire amount of bitcoin i needed available in one go, i was able to essentially pre pay him and he would have the remainder of balance to me as soon as humanly possible, shifting with the prices in my favour, and coping it sweet when it would have been in his interest to have a wine about it, i can not vouch for his integrity enough.