I think a lot of people are confusing wholesellers/volume resellers with actual distributors. Of course a simple sales guy with 10 of an item can label himself a distributor.
Many true distributors want large volume orders, why? because every order takes about the same amount of time to process and it's usually the smaller orders that cause the most grief. Usually most top level distros have more business than they can handle which is why smaller mid-level and low-level distributions are created.
Pricing varies from distributor to distributor. I know with car parts and the like it's not really how much you buy, but what kind of facilities you have and staff. A multi bay shop with trained mechanics usually gets the best terms, however, these terms may only be 5-10% different than what Joe Schmoe with a reseller certificate, business license and using his apartment number at his parent's place as a 'suite' number. Most I spoke with wanted pictures of the shop, a matching lease or deed to the address pictured, credentials on any employee you are claiming as skilled, financial statements with a listing of business accounts linked to the same taxid as the resell cert, etc.
There were many also that were just happy if I would send certified funds.....
The best deals usually come from the hardest vendors to find when dealing with foreign products as almost 100% of who you deal with stateside is just a glorified reseller....some do have actually warehouses here though and can give you as good a deal (better since they ship in huge volume) than dealing with their overseas centers.
There is no set answers....dealing with computer products is a way different niche than say silk flowers or pokemon cards. There is markets for food products that behave way differently than clothing...etc.
One of the best methods though is if you are importing to incorporate some sort of exporting also....if you want something of theirs chances are you have access to something they'd want from here.
I looked a lot into doing this, but I am a little burned out from college -> a ball and chain job for 5 years that paid me enough to buy whatever I wanted but time to spend my money -> college again -> making some mistakes

and what not -> several dead end jobs I jumped back and forth to until working for myself for 2 years. It was decent money but there wasnt enough steadiness to it and I wasn't large enough to really take on more. Some weeks I'd make 3k others only $400-500....if I was 10 years younger that'd be cool but I need to get some savings and real estate going.
My current job/career is a good one...a lot of responsibility but good work is rewarded/recognized. I get a nice work environment and everyone gets along, jokes, and in general you know who you are working with as opposed to the dogma of 'no talking cubicle workers' that work in a place 5 years and don't know the guy 5 cubes down.
The best bet in life is to work for yourself. You may need to take 5 years to make it and struggle doing so, but once you get something off the ground you will be rewarded with anything you make going directly to you and then you can decide how it's divided amongst the bills and income.
My brother got a good business off the ground off $10k on a CC which he paid in full within a month and then doubled that each month for about a year. He may be moving 2-3million through the business now in it's 5th year (I think), we was profitable and fully in the black after 2 years which was a huge rarity. The big deal on the whole thing is he no longer works at it really, he has his own career (he is a CCIE/Chief Technical Officer for a large private ISP) and his g/f is the manager and he has two guys on staff....he bled though for the first 2 years working 12 hours at his real job then until 2-3am getting orders out.
Good luck