$500-$600 is rip off considering they're probably no better quality than the cheap Chinese knocks on eBay. You can get remanufactured Bosch on eBay as well, but I'd shy away from the Chinese vendors.
I got a set of remanufactured Bosch 746s from John over on the
www.cherokeeforum.com (pm him at
hc7399). He's pretty knowledgeable and only charged $70 for a set of six 746s which he cleans and <b>flow tests</b> and had to me within the week.
They worked great in my 89 MJ that started leaking from the injectors.
