Cost of move was only one of the reasons. Yet, there were many others,
Just a few examples >from my family.
1. My grand grandfather went to the US in 1913 alone, leaving the
family behind him in Belarus, a part of the Russian empire. The idea
behind this was that it would be easier for him to settle there alone,
make all the arrangements and the wife with 8 children would join in
2-3 years, when everything is ready. It was a popular state of mind at
that time and it could work, if not for the reason #2.
2. In 1914 WWI broke out, followed by two Russian revolutions and
Civil War. These were really hard times, and travelling via Europe was
an enormous challenge, full of life dangers.
3. It was not before 1924 that my grand grandfather managed to invite
his family to the US, However, the Bolsheviks did not give permits to
children above 18. So, the 3 elder children had to stay in the USSR,
including my grandfather who had married and born a child (my mom) by
4. The 3rd brother that was still single managed to escape >from the
USSR in 1925 via Latvia, being smuggled in a ship's cargo deck,
reached Canada and only then joined the family in Cleveland, OH.
All these challenges were naturally on top of the cost of move.
And I believe that almost every family had to overcome its own hurdles.