I have a couple thoughts that haven't been brought up. First, machine embroidery is an addicting, expensive hobby. Besides the machine itself, you have to invest in thread, stabilizers, designs, possibly software, etc.. It takes time and practice to learn which stablizers and methods work best for you so there is an extensive learning curve. No one product is right for everything. Like you, I thought I just wanted to embroider my quilt labels. 2 years and three machines later and I embroider almost everything I get my hands on, lol.
Second thought. if you're going to get a machine with only a 4" hoop, you'll have to buy some tiny fonts to make quilt labels, and depending on the editing capabilities of the machine, you may need to buy software(more$$) to design your labels. And tiny lettering needs thinner than usual thread to make the letters stitch out sharp and clear. More $$.
If you're set on getting an embroidery machine, I'd suggest getting the Brother PE770. It has a 5x7 hoop, it's a good user friendly machine, and it's popular enough that if you decide machine embroidery isn't your thing, you'll be able to sell it quickly.
You might want to see if someone in your area that does machine embroidery could make your labels for you. I've made quilt labels and clothing labels for friends.
Cari