G'day Lee,

the Pentax is $619 at site sponsor B&H plus circa $60 delivery

http://www.bhphotovideo.com/c/search...250+4291284238

pentax lenses have international warranties & B&H are a authorised retailer, I have purchased from B&H and have always been happy

so it is about $550 vs $680

have a look at the lens reviews at pentax forums (both for pentax lenses and 3rd party) and photozone.

both are good lenses............not much help am I !!

is weatherproofing important to you?

cheers,
Tim