Pretty much so. Obviously I'm not going to try to nail down any precise proportion, and I'm not even touching "sentimental value". But the bottom line still stands.
Prices where I'm at may be a bit different, but if I put a department store bike at 100%, the cheapest rear wheel I can buy OTC is 30%. If i had to pay someone to move the cassette, tube & tire over, and to set the brakes for the new rim, I'm easily looking at +50% of the purchase value.
And a proper bike store wouldn't sell such a basic, noname wheel, so asking them for a package deal on part AND labor wouldn't improve things - rather the opposite.

Now, keep in mind that even BSOs tend to do OK for casual riding as long as they're new and shiny.

Unless I'm absolutely strapped for cash, and/or willing to swear blind that the rest of the bike is in pristine condition, I'm quickly reaching the point where getting another BSO makes more sense than repairing the old. Do I need to replace the cables any time soon? That'd be another 20% if the lbs do it. Brake pads? About the same. Assuming one more "repair" in the foreseeable future, buying a new bike is maybe 20% more. But that gives me a brand new bike, all clean and shiny. It's a pretty good bet that it would offer more value for money.

And don't be too literal about "real" bikes. I'm mainly trying to fight the mathematics.
Most people expect some proportionality between initial purchase and cost of repairs, having to tell them that whatever they need done will be a significant fraction of the initial cost tend not to sit very well.
And that's just the first repair. If they get any kind of mileage in the bike will soon need more TLC, and then you're back to square one again. It's just bad use of money. Every repair will pretty much also mean an upgrade, and we all know how that story ends when it comes to adding up the sums.
There's been a few department store bikes sold over here that were so poorly made that they were outright dangerous to ride - at any level. They eventually triggered warnings, recalls and whatnot. Obviously it's in everybodys best interest to avoid those.
Then I've seen one that was bought by a MTB club with the explicit purpose of testing it to destruction. They had all kinds of troubles, dropouts getting warped, bent brake arms, bent chain rings, bars pointing every which way after a drop etc.
For more normal use, that bike would have been entirely acceptable. Heavy, clunky, sluggish. But not dangerous and more fun than walking.
The bike I ride the most, my commuter, is definitely an inexpensive bike by most regular rider's standards. But it's still good enough that a new fork is an acceptable fraction of its value.

I'm really not trying to be a snob about it. But if you're going to use a bike enough for it to require more than token maintenance, it sure is easier if it's worth it.