The UK’s “altruistic” system means surrogates cannot advertise and may receive only “reasonable expenses”.
Experts say this should cost no more than £12,000.
In Ukraine and Georgia surrogacy costs between £30,000 and £50,000 through official clinics.
In Canada it varies from £70,000 to £80,000. It can be cheaper in unregulated countries such as Kenya, Ghana and Nigeria.
Publicity surrounding celebrities who have had children this way has made commercial surrogacy generally more accepted.
Kim Kardashian and rapper Kanye West’s third child is being carried by a surrogate.
Film director Tom Ford, singer Sir Elton John, and actresses Elizabeth Banks, Nicole Kidman and Sarah Jessica Parker also have surrogate children.
However lawyers say it has a “dark side”, following an increasing number of cases in which couples are facing legal problems due to poor regulation abroad.
In some cases, surrogates have vanished or tried to extort more money before the child can be adopted.
Couples have also had problems getting immigration status for the baby.
Others, unaware of countries’ complex laws governing surrogacy and immigration, have become embroiled in legal disputes.
Rose-Marie Drury, a surrogacy law expert at Mills & Reeve solicitors, said: “People going abroad for surrogacy are not always aware of the legal problems that can arise, resulting in potential heartbreak.”
Gemma Whitchurch, of Irwin Mitchell solicitors, said: “Many people see going abroad for surrogacy as easier but parents are risking the legal status of their intended children and even exposing themselves to the possibility of handing over their life savings to people they don’t know without coming away with their baby.”
Three years ago the family court heard the case of a couple who had paid £26,000 to a surrogate mother through a clinic in Ukraine. However, civil unrest after the baby was born meant it could not leave the country for six months.
The surrogate and baby then disappeared.
A couple who paid £10,000 to a surrogate mother in South Africa were refused their child until they paid thousands of pounds in additional fees.
The number of parental orders – needed to adopt a surrogate child in the UK and abroad – has risen fivefold since 2008 to 350 in 2016, Ministry of Justice figures reveal.
But experts say this is the tip of the iceberg as many do not apply for an order.