The reason you have lower carat gold for jewellery especially rings is that gold is a soft metal and without a decent alloy it will easily deform, if your buying jewellery for an investment I would caution against it unless you are buying second hand like @fat-elvis who is buying just for the weigh. Gold jewellery usually has a mark up of twice the price of spot, so unless you love a peace or if it is so cheap it's near spot buy bullion.