I'd definitely go yardage since even without a specialty ruler, 10in squares are pretty quick to cut. Sounds like a new mat would really help you plus it's something you'll use often. If you know anyone with a Stripology ruler, it would make cutting layer cakes really quick (plus any other strips you'd want). I just invested in one a couple months ago and absolutely love it. I can cut a charm pack in about 20min starting from ironing the fabric to getting accurate squares. Ridiculously fast.