[ycombinete]

First thing would be to quickly identify which cards are valuable. This can be done using phone app scanners like the TCG Player App, Delver lens etc. They auto-scan the cards in and give you a value based on the mid-price in the market. For p2p sales TCG's mid-price is usually used as the de facto value of a card.

If you are in the USA you can send cards in bulk the CardKingdom.com. I know some people that even did this from outside the USA.

[KingOfCoders]

Sadly in Germany :-( Perhaps a reader knows about a reputable bulk service here, good point.

[ycombinete]

Your best bet might still be to use Card Kingdom. I've had friends ship their cards from countries in the middle east over to card kingdom when their collections were large enough. For smaller collections Ebay, and even local game stores in the area should work fine as well.

If it were me I'd find a local game store, and go ask the guys there what they use.

[KingOfCoders]

Good point, Card Kingdom currently does not buy bulk but I'll wait, seems legid.