Sure seems like you're comparing Apples to Oranges. The Gios is a good mass produced lugged steel frame. I don't really know an awful lot about Pergoretti's myself but you can get a great custom made frame in your choice of tubing from a large variety of highly regarded builders for a lot less than 4 grand! Yikes! My advice would be this depending on YOU:

1) You just want a nice steel frame road racing frame: get the Gios (though there are other competetive options).

2) What you really want is a good custom frame: lots of options less than $4k. I understand Pegoretti makes a good frame, but there's no magic to it. I bought a Mercian but I'm sure the members here can provide you with close to 100 options.

3) What you really want is a Pegoretti and you have the means: buy the Pegoretti.

Chris