The website contains c.a 30.000 products divided into 12 categories; second division is by specific use. 80% of them regard items which can be considered medium difficulty in Google.
Unfortunately, all product info is not unique content.
The target is to reach 300,000 UU / month in a 6 - 9 month period of time from scratch, with a reasonable bounce rate (below 48%), and keep a similar search traffic. Of course the task is about SEO, not about directing any trafic, as the traffic needs to be real, human, LOCAL and actually interested in the subject;)
I know there is a lot of factors determining the difficulty and price, therefore I'd expect an estimate cost for the whole period of the first stage, needed to reach the described level.