inbound - 12:13 am on Apr 7, 2007 (gmt 0)

The best option is to automate the pausing through the various API's. It should be fairly trivial to pause and resume ad groups based on stock levels if your inventory system can trigger external events based on pre-defined stock levels (such as re-ordering or alerting someone that the stock is getting low/sold out).

It all depends of the scale of your campaigns, if you are spending sufficiently then it will be worth every penny. I suggest reading through the features that can be triggered through the API's, you might come up with some things that get rid of time intensive operations. The trouble may be finding a suitable programmer, it's not hard but you will want it to be 100% correct on the first attempt.

Good luck