Too low? Lol, not with the majority of the playerbase you end up pugging with. Remember, if you have the skill and knowledge to do heroics as a fresh 85 you can always group with friends and knock it out regardless of your ilevel. The gear limit is only there prevent undergeared randoms from grouping together and getting roflstomped(not that it really helps when you're with bad players) in heroics.
Can a 110k hp tank do heroics, sure. Just like I could heal heroics with 60k mana when i hit 85. Doesn't mean it's a good idea when you're doing randoms and potentially grouping with other undergeared players or people who don't know how to play. I just got out of a random with a lock who did not know what banish was. No amount of gear will mitigate that.
Still, if you're starting out, and you're doing a critical job like tanking or healing, the least you can do is get some green gems and some entry level cata enchants/ wrath enchants(which are dirt cheap now). A random gives 80g for the first/ 40g for subesquent. Gold should not be an issue if you're planning on doing lots of heroics. Start buying flasks, top tier enchants etc for raiding and come back and talk to me about not being able to afford stuff. If you can do heroics with subpar gear, that's wonderful. but dont walk into instances with 0 effort put into your set aside from the time it took to get the drops and get upset when healers complain about your health pool and lack of avoidance.