You know you've crossed a certain line when you can start a bar tab without a credit card; you've gone fancy. Like, maybe that credit card won't be able to cover the two drinks you just ordered. Add to it a bartender who pours your bottle of Heineken into a glass like it's holy water and you may well have crossed into the land of high livin'. It's not what you expect rolling up to Club 347, a tavernish (on the outside) little spot of light in a dark-after-5--save for the looming Mercy Medical Center--zone at the northeastern fringe of downtown. Inside, however, is a surprisingly rakish jazz club/bar full of well-dressed older couples and formally clad bartenders and cocktail servers. But, 347 is anything but snooty. Our bartender was exceedingly warm and courteous, ready to offer another beer the moment we got down to a last sip, and the owner wandered the room smiling and greeting customers as a jazz band grooved up front. It makes up for a barely there beer selection, a somewhat lackluster room--like a cross between a hotel conference room and a hotel bar--and a location not on many beaten paths, unless you're a doctor. And those two drinks? $9. We can handle that.