yeah, if you want a motor with less than 30k on it, youre gonna have to buy it brand new from the dealer. inlinefour.com is WAY over priced on their motors, if i remember correctly their 98 spec B18C-R's are about $5,500.
www.hmotorsonline.com has good prices on their motors, they have a start up guarante and they guarante all sensors and components.
www.jdmhondaparts.com also has good prices, they have a start up guarante, but they don't guarante their sensors. just shop around, i'd also suggest checking out a few local shops about prices and warranty's etc...