Obviously can’t repost until the 30 days is up but if it is imo you’re way better off re-posting if you can spare the extra few minutes. I don’t have stats to compare but I’ll eat my hat if you can prove that the extended ad gets more views over the next 30 days than a reposted one 
the one benefit to extending that you’d be giving up though is that if your ad was in the “bargain bin” it would no longer be as a new ad.