While the end user would have to be careful how they use the site, I don't find "ipad hacker" inherently infringing.
The downside to the domain is that hardware hackers usually have their own websites already with a built-in audience. I don't think you're going to see a lot of end user interest.
For fun I'll toss $10 out there as an appraisal. Maybe higher if you really get the right end user. But, marketing minded hardware hackers are very few.
The one thing I'll say on this topic is that "whateverhacker" is usually a weaker search term than "whateverhacks". Also, that demographic is a real pain in the ass to monetize. They tend to take the info, and never pay for anything or click any ads.