If you want to fly on DL, earn VS miles and book DL flights using VS. That is the only way to get more normal (still high, but not absurdly and arbitrarily high) pricing.

As for the DL FFP, you cannot use DL miles to originate in Europe or North America. That is when pricing is off the charts (as in literally, there are no charts, and pricing is closely tied to revenue - the years ago leaked "EOS" [End of SkyMiles] that DL was hiring for is indeed here - and you will get about 1 cpm value). If it works for your travel, buy a ticket to, say, ICN, and then use DL's SlyMiles to book ICN-xxx (destination) flights. That is the only way to get somewhat reasonable pricing in the DL SlyMiles FFP: do not book any award flights with origination in Europe (if flying to NA) or North America (flying to anywhere), or vice versa.