3 stone princess cut on a budget

[angels5]

 

[angels5]

My son who was supposed to get engaged in Dec, for a long engagement is now getting engaged this month. $ avail have been decreased due to surprise start of a family. He''s got under 1,800 to spend and is hoping to get a 3 stone princess cut. I''m taking him to the jewelery district Sat. Any suggestions on jewelers would be appreciated. They are 19 & 20 & I''d like to see them get a decent stone, but the biggest bang for their buck. Is there a noticable difference between SI3 & I1? Is there a noticable price difference?

Thanks