Small amounts are easier to get through customs in most countries, even notoriously strict countries.
Even after including all the equipment cost still cheaper than buying UG or pharma.
Easier to know what you have. It is pretty easy to test raw powder by meltpoint, smell, etc.
Have to read up on home brewing. Plenty of sites on the net, but you still have to do the work and it is fairly time consuming vs. just ordering from a reputable source.
Powder may get treated differently than pre-made by law enforcement. Depending on your jurisdiction, powder is far easier to upgrade to distribution. The friends I know have always kept powder quantities to slightly large personal usage amounts and they have only received seizure letters, no home "visits".
Just as easy to get burned with crap raws as pre-made. Have to know your vendor.
FYI, there are plenty of websites for chinese generic drug manufacturers. It is so easy to find a good source, the problem is importing...