I have hair like you - very long and tick, sheds a lot. It does put a lot of wear on my Roomba which runs every day on carpet. I find the CHM (cleaning head module, which is the easily replaceable part that contains the gears, brushes and motor) needs replacing every 6-8 weeks. The carpet puts more drag on it too. I clean the brush ends off after every run and they always have my hair wrapped around.
However I still consider the Roomba WELL worth it, it works great cleans great and never gets stuck and makes its way back to the dock every time. It keeps the carpet very clean and I love coming home to a clean carpet. It keeps the cat hair from building up or getting ground into the carpet fibers.
Mine is still under irobot warranty so they send me a new CHM when it breaks. I bought the Roomba at Hammacher for the lifetime warranty but I am now unsure how valuable that warranty is in my case since I'd have to send back the entire robot and pay shipping (irobot just sends me the CHM which I can replace in 2 minutes myself).
I would recommend getting the $250 Costco 550 with aerovac, for the first year you will get free CHMs if they break and after that you can buy them for $50.
I figure it's still far cheaper than hiring a housecleaner!