I'm addicted to spray starch. I just love using it on my quilt blocks, and love spraying away as I put a quilt top together. Yep, I use steam too, but spray starch is my real best friend.
My very favorite is Mary Ellen's Best Press, in the linen or lavender scents, but it can be pricey. Amazon has the best price that I could find. I have Amazon Prime, and shipping is free, so the cost is the net cost. It's $11.84 for a 16 oz spray bottle ($ .74/oz); $14.95 for a 32 oz bottle ($ .46/oz); and a gallon (120 oz) jug for $38.63 ($ .32/oz). It's probably cheaper at your LQS or craft store, but it's still not inexpensive.
On the other hand, good old Niagra Spray Starch is $2.29 for a 22 oz bottle, or $ .10/oz. I buy it when I see it on sale, and usually three bottles at a time -- one for my sewing room ironing, one for my laundry room ironing, and one as a back up.
I have a good friend who recommends spray sizing instead of the starch. She is in the habit of washing, ironing & starching her fabrics before adding them to her stash. Her hubby was in the military, so she's packed up and moved that stash more times than she could count. Well, starch is cornstarch-based, corn starch attracts little buggies, and my friend learned the hard way that spray sizing was the ticket, not spray starch. I could only find the sizing in an aerosol can, but prefer to stick to non-aerosol if it's available.
I don't usually pre-wash, so I'm OK with starch, but if you are a washer/ironer/storer, you might want to stick with the sizing. Are you a starch-oholic?