Rapid7 Offer evaluation - keep interviewing?

Received a verbal offer from Rapid 7 for a senior/lead position. I am not sure yet about the offer detail. But it should be close to

TC: 300K
base: around 210k
bonus: 10-15 %
RSU: 60K-70K / year

YOE: 3 + PhD

My goal is to bump my TC to 400K-500K. I haven't started to interview tier 1 companies. I want to collect some advice on whether I should try to negotiate this offer? Also, if I managed to negotiate a better offer (e.g., 350K), should I consider not to keep interviewing?

PS. Let's assume I am ok with the team and the problem domain.

#offer