FILL PRICES AND GUIDELINES Fill – 1 week $30: Must less than 8 days. Only available after a full set from BX Lashes. Fill – 2 Weeks $45: Must be 10-14 days. Only available after a full set from BX Lashes. Guaranteed doesn’t matter how many lashes you have remaining, you will be paid 2 weeks fill only. Fill – 3 Weeks $50: Must be 17-21 days. Only available after a full set from BX Lashes. There must be 35% of your lash extensions still on to be considered a fill. Anything less or anything after 3 weeks is considered a overdue or full set and a full set price will be charged..