In reply to Cookio:
technically wild camping is illeagal in the alps, but it is perfectly viable to bivy on the route. there is a recognised bivy spot near the tete rousse hut, which is probably a more comfortable spot but makes for a much longer summit day. I bivvied right next to the old goutier hut, literally on the balcony ledge. made for a stunning spot to watch the sunset but did mean I got woken up by early starters heading up from the lower hut!
its always far more rewarding to do things unguided, and mt blanc is non technical. but that said you still need substantial mountaineering experience to do it so only you can know if you need a guide or not.
if doing mt blanc then base yourself in the campsite in argentiere if you are on a budget. stay as long as you want/need. you can pay a reduced rate to leave an unoccupied tent up while you are on the hill.
there is no shortage of acclimatization routes to do in the Chamonix valley to suite all needs and abilities. the more you can do the more you will be able to enjoy the final slog to the summit of mt blanc!