I've ordered a bunch of stuff. here is my experience:

For starters, make sure you both agree on what condition means before shipping. International returns are a pain in the ass. Expect over-grading across the board.

Depending on where it's ordered from average shipping time from Europe to US is usally 7 - 10 days. Sometimes they have problems. My last record came 6 days later than usual because of a supposed shipping strike. He tried to deny it until I pointed out the date is on the postage and he finally admitted he really didn't ship it until 6 days after he marked it as shipped in Discogs. So expect to wait at least 3 weeks before having to open a complaint.

Packaging has been about 50/50 ok or total crap. I've had people try to just put it i paper sleeves and mail. Most use a record box of some kind. Discuss this with the seller before agreeing. In any event it is the seller's responsibility that you receive your item undamaged per the PayPal agreement. So you are always covered on PayPal's side for a damaged item. Regardless of what the shipper might say.

Shipping can be pricy. Expect prices between 8 - 20 euro depending on service, location, and how much extra they want to charge. Have them provide tracking immediately to avoid complaints about delays. Communication is key.

Over-all, my experience with international orders is not as good as local. More problems with grading and shipping packaging mostly. Poor communication. But not that far from what is par for the course when buying anything on Discogs these days. The more you work it out before making the purchase, the better off you will be.