Yes, it is custom, but in Chicagoland area some of the LA charge 2 different rates for custom quilting depending on number of different motifs -- and also charge depending on whether you change thread color. You should be able to keep it all one color thread which by us would run between $0.04 - 0.05 per square inch. Oftentimes on a LA I see them charge more money for straight line quilting ("ruler work") than for FMQ. If getting a reasonable rate is more important to you than having crosshatching as your design, you might consult with your LA to see what options she has that might save you a bit of money on the quilting.
And if you haven't made them for someone specific, you could always donate the tops to a charity (I take in tops from our local Quilts for Kids to custom quilt for free because I like quilting much more than piecing) and start some new ones that are QAYG so you can load them on your machine and just do an hour of quilting at a time -- if quilting is something you enjoy. I have a Bernina 350 with a 5.5" harp & actually am able to fit a Queen quilt under my machine with low-loft batting. Maybe something to keep in mind for the future -- though I definitely understand that there are only so many hours in the day & at a certain point quilting can turn from something fun & relaxing into a stressful chore and none of us want that!
Hope you can find something that works for you!
Bree