Scott,
This is true. I buy 130-volt 60 watt bulbs and they're probably using maybe 50-something watts and putting out a tad less light than a "normal" 60 watt bulb would.
I've gotten used to the slightly reduced light output though. It's barely noticeable.
No, I don't buy bulbs at supermarkets or grocery stores. I get the 4 packs from dollar stores or job-lot stores.