I think it is much easier now than back in Wild World. Now there are so many ways to earn bells quickly, like selling other town fruits, catching beetles on the island, turnips or planting bell trees. In Wild World I was always poor and it took forever to expand my house to the max, because you could only rely on catching normal fish and bugs. Maybe there were some tricks back then, but if there were I defenitely didn't know about them.
I seem to remember there being turnips in Wild World, too. Red and white ones I believe, one of them cost more and you were supposed to bury them or something!
It’s definitely easy to make bells, though. Even if you don’t want to slave away on the island catching bugs and sharks there’s always TBT and users willing to sell their in-game bells.