Paying for IVF

After 9 months of clomid, femara and multiple IUIs we feel like moving to IVF is our best option. The IVF lab is separate from my RE and doesn't accept any insurance but will do a courtesy claim after the fact, so it is possible to get a refund if we overpay in the beginning, but since it seems we must pay upfront I was just curious how others have paid for IVF. Simply saving up money, taking a personal loan/loan from retirement, getting an extra job, etc.?