Database Driven Web-hosting Solution

I am developer and I ahve done web-site development and database development but it was for other companies where everything was already available.

I was not sure if this was the right place for the post, but I thought I would atleast start here, if I should post this in some other category please let me know.

I am satrting work on a Database driven web-site. I say database driven, becuase the web-site copares prices for multiple products. By some worst case scenarios(explained later) I need a database to easily acoomadate more than 1000 GB of data. I can definitely try cutting this down, but my question is what type of hosting should I choose and how when the web-site is completely relying on data that is updated on a weekly basis.

The reason to keep old data is to use that to show a Price history and forecasting on future Prices. The thought of storing this data locally and just creating a summary has crossed my mind.

The Data Scenario:
Price of Products per store: 50,000
Approximate size for the table per store: 3 MB

Number of stores: 500
Avg Size: 1500 MB

This is the bare minimum 1500 MB + other tables + overhead

Other tables: Forum data, Reviewes, User Favorite Products, etc.

Number of weeks: 52
Avg Size: 78 GB

Howevere the table with the most data and the table that would be changing the most is the Price table. So I am approximating the minimum requirement for the Databse to be atleast 2GB.

My question now is:

To be cost effective I can store the history on my personal desktop. But I still need something that allows me to have 2 GB of Database space. What is my best solution?

I have no strict rules about platform or langauge, to get started I am just trying to be cheap but still find a decent web-hosting solution so that by getting started small I have hopes of going big.