That photograph scares me. I'm an architect who worked for a while as a metal frabricator and I both know the look of a good weld and have to inspect them frequently on job sites. I wouldn't ride that bike unless I was being paid to and moving under 3mph.

Some cheap bikes will get you going, and at their best they're just clunky but do the trick. Be careful though, bicycles are under huge stresses and if they are improperly assembled they can break an hurt you very badly. A good weld should be very even looking with all of the ridges about the same distance apart and going the in the same direction. There should be no spatters or burrs, and no lumpy knobs sticking up. If theres a hole anywhere in the weld, put the bike back on the rack and leave the store.

I like riding old bikes, but I'm not going to say don't buy a bike from walmart. These days, the technology on a good bike is so good that I'm sure some of that has filtered down even into the cheap stuff. Good Luck!