If you're not going to be doing comps with the COC's then get a set of heavy grips from eBay for $60-$70.
If you get 100, 150, 200, 250 and 300 grippers you should be set.
I'm about 4mm from closing on the 250 which is in between a COC 2.5 and a COC 3. Have closed a friends COC 2.5 but it...