It has never been a problem for me in the past. It is also something most of my dive buddys do. I have only had one o-ring fail on us the entire summer, and it was operator error that caused the problem. It happened before the dive and of course I had plenty of extra.

By the way, do you really think the hardware store o-rings are not as good as the ones from the dive shop? My thought is the "standard" o-rings (like the ones from Trident) that you buy at the dive shop are IDENTICAL to the ones from the hardware store. I bet they are most likely made in the same factory, but have different packaging. Of course as soon as the SCUBA name is added, the price goes up.

Now if you are not using standard o-rings then that is another thing altogether. I still have about 60 dives on the same hardware store o-ring without any problems.

And don't fool yourself, ALL o-rings will fail, even Papa Bear's White Gold ones. It is really not a big deal because the large majority of the time this happens before the dive and is corrected.