I can confirm in Incognito mode you are ranked at the bottom of page 1, but only us SEOs use Incognito mode - not your average Google user.
We had a similar problem and no matter what I did I couldn't get the ranking to change constantly.
The strategy I took, was to look at keywords people we're searching for before the 'money' term and get content to meet the searches needs. Less competition usually so rank higher.
Google will rank sites higher where users have visited before and had a good experience, so if you can get people to your site before they know they are looking for wholesale jewellery, when they come to search the terms as well as you ranking higher, you will also have some brand loyalty so more likely to get clicked.
If we still had keyword data in GA we could prove this theory but I get more organic traffic to the page I was trying to improve.
Hope this helps. While you might not improve in Incognito mode - you will get more organic traffic and more sales.
Hope this is useful.
Thanks
Andy