New member interested in selling pair of Vandersteen 1ci; sane shipping methods?

Hi,

I'm a new member here and wanted to list a pair of 1ci's as well as some headphones (Ether 2 System and Audeze LCD-2). However, I have no idea how on earth to calculate and list a real, reliable, and sane shipping price. I've tried UPS and FedEx calculators, but in the latter case I got a quote for $5000 to $8000 dollars for shipping alone, based on estimates on dimensions and weight I gave. I was planning on selling this pair of speakers for 4-500 dollars, so obviously these options won't work. 

How do others manage this factor in creating listings? I have a long history of selling things online, primarily vinyl records, but I've never shipped anything so large before and the services provide little to no help in trying to resolve this question. Clearly something isn't right here, or else no company would stay in business since they could not sustain these shipping rates I'm getting quotes for. 

I'm used to selling things up to maybe 10 pounds in weight, so I'm just clueless here as to how to begin. I have everything ready for a high-quality listing, but I can't complete the listing because I have no idea how much shipping to charge.

I apologize in advance if this is a silly question, but I wanted to make sure that my first listing is an accurate one that will not create any problems for myself or whoever might want to buy from me.

Thanks to anyone who can give me some guidance here! Anything like a realistic shipping calculator you're aware of or even general rules of thumb for costs would be helpful.

Thanks again,

G