You would only be reasonable if the NHS offering here were adequate, and private treatment costs were reasonable.
As it is, NHS provision is dire, there’s a complete postcode lottery and many couple don’t get treatment. If they do, the offering is usually a small number of one-size-fits-all production line treatments that aren’t properly tailored to the individual couple, and don’t take advantage of cutting edge treatments or labs.
Private treatment is eye-wateringly expensive, and simply out of reach for many. Not just because of the stringent regulations here, but because of the clinic profits, which are hefty.
Often, clinics abroad are more efficient than the ones here, even private ones. Spanish clinics, for example.
There are obvious reasons why people go abroad. They’re desperate and often this is the only chance they have to become parents.
This is a systemic issue.