Dave,
Once again, it is you disputing the claim, Keith, and it is up to you to disprove it.

You have made a claim but you can not tell us why you believe it.
You have no evidence for your claim.
It is just another of your whims.

If an importer overcharges for goods, a competitor will undercut them.

Or you could stick to the point and tell us all the benefits that post brexit UK will reap.

Just a few examples then Dave.

Cheaper food and clothes estimated to save the poorest 20% of their spending.

The freedom to make trade deals with anyone we want.

Not being shackled to "an institution which is driving and reinforcing many of the problems across Europe, from the refugee crisis to worsening work conditions, to a growing militarism. While it is continuing to penalise Greece, it turns a blind eye to far-right politics in Poland and Hungary, and looks like endorsing the return of Silvio Berlusconi in next month?s Italian election."

The right to control our own borders.

A fair deal for our fishing industry, ravaged by the EU since we joined.

Helping developing nations by removing tariffs from their produce.
Freedom from EU bureaucracy.

Restoring power to our own Parliament.
etc.