There's a huge variety. An individual subscription to Nature is $200/year[0], but they often charge $30 for electronic access to individual articles.
An institutional subscription to the Astrophysical Journal is $2000/year[1], though if you're a member of a professional society, you can buy an individual, electronic subscription for $25[e.g., 2]. As a point of comparison within astronomy, a similarly prestigious journal, the Monthly Notices of the Royal Astronomical Society institutional subscription is $9400/year[in the csv link in 3].
[0] http://www.nature.com/ecommerce/subscribe.action?productId=n...
[1] https://iopscience.iop.org/journal/0004-637X/page/Pricing%20...
[2] https://aas.org/individual-membership/dues-subscription-fees
[3] http://www.oxfordjournals.org/en/access-purchase/pricing-and...
Anyone have any rough numbers on what this would cost Joe Schmo to buy?