It is expensive to collect fabrics if you buy in retail quantities (FQ, 1/2 yd, etc). My wife and I collected half yards for a few years before we were able to make the I spy quilts we wanted. We would buy a couple of fabrics each time we made another purchase and store it all together. When we got 130 fabrics we cut them into 5” squares and made them into 24 kits.
I know you said you’d like to have them all together at once, but we never found a source to buy kits ready to sew, so that’s how we did it.
Good luck.