You should try 7.5# jumps. A pair of 1.25# plates costs about $9 from amazon. http://www.amazon.com/Grey-Machined-..._bxgy_sg_img_b
I am going to be switching to 7.5# jumps now that I've finally hit 350lbs on my squat. Maybe it's stupid for the squat but I know you'll love these plates for your presses if you don't have them already. I just really like the idea of getting an extra 5# gain in 2 sessions over what I would get with only jumping 5# each time.