That looks a lot similar to the one i just bought for £50.
In the fact it has peugeot written on it and has a diamond frame with wheels and handlebars it is similar.
However the Perthus is Reynolds 753, Mavic MA40? rims & very decent spec components.
Unfortunately the Premier you bought doesn't hence the massive price differential.
£310 was probably all the money if it's in good shape but certainly not over the top when you consider what you actually have.
1958 Carlton Super Python
1990's Gitane VITUS GTI Triple Butted
1996 Raleigh Titanium Special Products Division
2007 Specialized Globe Pro
2007 Specialized Globe Expert Ultegra 6700
KTM Strada 6000 Carbon Dura Ace 9000