Shipping my Wide-angle Lens to Ecuador (Guayaquil)

Hi, I am trying to ship my wide-angle lens to Ecuador (I'm a newbie photographer) and it is under the 4X4 limit. It only cost about $350 and I'm sure it weighs less than 4 kilograms. I just heard however that it still may get held up in Customs. Who can I contact to find out current law and what procedures do I need to take to not have to pay through the nose to get my lens cleared through customs? A friend of mine had to go through hell and pay beaucoup bucks just to get his $50 prescription eyeglasses which clearly was under the 4X4 limit.

Thanks