The nRFgo Development Kit for nRF51822 is only $100, and comes with a Segger J-link Lite which is limited to nRF devices (or maybe a subset of them).
Olimex seems to be the only other viable option I can find. THIS might do the job. I don't know if it supports nRF parts, but it seems to have plugins for IAR and Keil (though maybe not perfect). THIS is another Olimex product. this has some info on trying to get Olimex products to work w/ the nRF51822
From all I've read, though, Segger is the way to go. The base unit, if you don't go with the DevKit option, should run around $350. That will work only through an IDE, and doesn't include a production programming environment. For your part count, though, that should be fine, and there's probably free Flash programs w/ Segger plugins, anyway.