Double Bed mattress BRAND NEW

I bought this mattress last week, and as you can see, it was delivered on the 23rd. I mistakenly ordered the wrong size, and it is unused. The seller does not accept opened mattresses, and it's difficult for me to vacuum-pack it for shipping. That’s why I’m putting it up for sale. I purchased it for $349 before tax and nearly $400 after tax and the original value is almost $1500 as you can see. I’m selling it for $300 only, and it hasn’t been used at all.