I ponied up the $ and purchased my injectors from Heath. I got known genuine Bosch units with the correct nozzles, not suspect counterfeits that were in the other "Bosch" rebuilds. Manufacturing stamps were decidedly different between the two.
My 2 cents after conversations with local rebuilders and Bill Heath.
As for cost "savings", shops are going to charge for the genuine nozzles, which aren't cheap, and then there is the labor to assemble, test and adjust. Figure a minimum of $65 a unit and you're looking at a price of at least $500 for known good set. So, if you're paying under $240 for a set of rebuilds, the rebuilder is taking shortcuts somewhere in the parts or labor departments and probably both. You're running risks that may not be manifested for a while but certainly prior to the 100K miles one is supposed to expect. The set I had were showing deminished spray patterns after 10K miles.