if that $1500 includes the pek-hkg leg, i don't think it's too unreasonable because, since you mentioned dc, you appear to be originating on the east coast.

if are flying from nyc or was, you might be able to get the tpac for around $800 (probably on one of the korean airlines), then pek-hkg can cost as low as $150,.... but, that is a best case scenario..... i paid over $1100 for my last july tpac (bwi origin) because i wanted to stick wanted to stick with ua. and, be prepared to pay $300 for pek-hkg (though szx is always an option).

in any case, i suggest you check back in about 5 months or so.