I've got the June Taylor "Shape Cut" slotted ruler too. I think it was about $18 at Walmart. I use it all the time!
The only issue with it is if the size isn't based on .5", if it's 7/8, I cut on the next biggest slot, then cut down very carefully. lol!!!
But I'd strongly suggest getting this slotted ruler if you're able. It's made quilting sooo much easier for me! :-)