Declare the correct value on the Customs form?

Sorry but hope you can afford the loss. 

@OP Did you pay duties on receipt of the album and if so, did the seller declare the full value, i.e the price you were paying them, when they exported the goods to the US?

let me add a different perspective, with a European brain (Eastern European, even worse)

We deal with taxes and customs and fees every day. It's a nightmare. A price tag of X really means 3X at the end. It's pretty normal to be "lean" every possible way and use standard low numbers when declaring value. It can totally NOT be a red flag, just routinely avoiding getting screwed. Many times, customs doesn't care if it's an item returned back to its origins. They are trained to screw you. They have quotas. I could write a book about my stories sitting in their offices with my beaten up laptop as they claimed I was trying to sneak it into the country and sell it. 

On the other hand, $1200 for a record, not as described IS a red flag. 

@grislybutter do you live within the EU zone?

I once traveled from Rochester, New York, where I lived, to the IKEA store in Toronto. It was a long time ago. I had 7 foot tall shelves sticking 3’ out of the back of my hatchback car wrapped with 100 feet of saran wrap because it was raining like hell. The border agent ln Canada asked me if I had anything to declare… There was no cost to bring it over the border, butI am still laughing at it to this day and it was 35 years ago. 

I lived near the Canadian border. Everybody said DO NOT LIE when crossing the border, EVER!

Bent