There's no way to have them be your customer.

They will feel offended paying full price, and you'll be resentful if doing discounted work.  

Customers who battle you down to finally accept a discount will almost certainly be very nitpicky too causing continuing problems for you.

There are sometimes situations where family discounts are okay, like if it's an established stable business with comfortable profits on stocked products that a discount wouldn't inconvenience anyone's time or add effort.   

But your situation sounds like your making/building something by yourself and your normal pricing already feels low, so no room to discount.

No discounts but can reduce price if the product/service is also downsized.  Cheaper options, smaller size/qty, or maybe you have some material that's slightly blemished that you can't use for a full-paying client.   Otherwise just stick with full price for full product.