If you just want a few items for personal use go to
www.skybox.net. This is a LANChile service that lets you buy online in the US with a credit card and the stuff is delivered to your door, legally, in about a month. The total cost is generally double what you payed for the product. So if you go on Amazon and buy a toaster for $50 a total of about $100 will end up being charged to your credit card by the time it gets to you. It could be more than double depending on size, weight, etc.
On the other hand, if you want to do any serious importing, god help you. You definitely need a dispachante aduana, but understand that, though there are undoubtedly exceptions, this is a very shady bunch. At first you will be told that it's no problem. You'll be given a summary of the charges and procedures required by law. It will seem expensive, but not prohibitive. Once the products leave the US, however, things will begin to change. Unforseen 'complications' will arise. There was no way to know about these unfortunate complications, of course, but luckily your 'agent' has connections and can resolve the situation. It won't cost too much extra. So you pay. Rinse, lather, repeat. The further in you get the more it costs to walk away. Welcome to Argentina.
If Ye do decide to abandon all hope and enter here, start with a SMALL shipment and see what happens. Careful, though, your 'agent' will probably know you're doing this and make sure there are no problems until the big shipment comes through. You have to do many shipments, incrementing the amount slowly so there's no obvious point for them to turn the screw. At the first sign of trouble, walk away, tell them you'll take the full loss, you have no interest in pursuing the matter. You'll get a phone call in a day or so to patch things up. Agree to the extra fee, but NOTHING up front. You'll pay the fee when the truck offloads the stuff in your warehouse.
The current government is heavily protectionist and wants no major importing of any kind, particularly new players. So all the difficulties you'll encounter are ultimately sanctioned by and even encouraged by the government, so it will be a tough road to hoe. Not impossible, but not for the faint hearted.
Good Luck!