well, for starters, dont spend your advanced refine runes yet. Considering the refining rebate was last week, it'll be around a month or so until the next one, so right now you should focus on saving them up. Second thing is, lvl 6->7 requires medium refine runes. So, save up medium + advanced refines.

6->7 = 100 medium

7>8 = 200 advanced refines

8>9 = 500 advanced

9>10 = 1000 advanced

so, worst case scenario, a total of 1700 adv and 100 medium PER equipment, if you wish to get it all the way to lvl 10.

of course, there is a luck factor that comes into consideration when calculating this rough estimate, so it may be require less in some instances. regardless, to make the most use, ALWAYS wait until the refining rebate, as you will also get bonus wish credits which will take the required number of adv runes down.