For initial testing, I usually get the 250 round box of Berry's bullets as I like to try several different powders with start-to-max range load data (BTW, they come in nice reusable plastic bullet boxes they make themselves). Some times, I find that I need to do verifying range tests 2-3 times, so having more bullets definitely helps.
I was very happy with the results I got from the new 9mm 124 gr HBRN bullets so I ordered a box of 115 gr HBRN to test along with 45ACP 185 gr HBRN that has similar nose profile of 230 gr RN.
Jay/Berry's MfG provides great and fast customer service. Maybe he can put together Hollow Base sample packs? (hint, hint)