...For $100 though if you're just considering it being a frame, and a few other parts, that's not a bad deal.
You're going to need to buy a new rear wheel for almost any bike.
Odd as it may seem I agree fully, the exact same components that need upgrading on a $100 bike need to be upgraded on a $200 - $250 box store bike.
There is
very little difference between the two in quality. No additional care has been taken in frame design or manufacture, they've the same type rims, the same questionable components in general, the only real differences are in selection and gearing - a mountain bike w/cheese front shocks and/or multispeed instead of a coaster, maybe two brakes instead of jus' the one.
Granted, that extra $100
might offer a slightly better frame welds, but if you don't examine them there's no guarantee by price alone, the quality is still just as random with the second cheapest on the rack as it is the cheapest.
You can try to scrimp a few pennies here & there, you can tell yourself if it costs more it must be better, that you'll not need to upgrade anything because you got "this" generic instead of "that" generic but the fact remains no box store bicycle is perfectly suited for motorization without some improvement, most importantly the wheelset.
If anything those "$200" box store bikes are more likely to come with the dreaded single-wall alloy rims then the steel the even cheaper ones have, which are just as likely to fail as a $100 frame, or more so. Both have the worst quality components, the cheaper less of them is all (brakes, shifters etc).
It doesn't matter what bike you buy, you're buying a frame - everything else is pretty much either an accessory or will need some manner of modification or upgrade - I'd happily ride a Huffy IF the wheelset had been swapped out, brakes improved & frame examined for uniform welding, all the same things I've done with any other bike of any other price.
They're like any other low-ball retailer selling cheap crap - they know full well if ya slap a few stickers on it, jack up the price a bit, add a little hype & folks will be sure they're getting more for their money.
Start with a solid frame & build from there, don't kid yourself that a $100 price tag one way or the other is really going to make much of a difference. At the very least if you want a safer bike, you'll be buying a wheelset.
