Ask HN: My startup idea, What do you think?

Idea is to create a platform for buyers on how they shop for better deals or prices. It is a simple three step process

    1) Buyers can either from their phone or web make a post saying I need to buy flat screen LED 42" TV and my budget is $500.00.
    2) Sellers will response to the post by offering their prices either by matching or beating it. Buyer at this point can use the portal to ask questions or negotiate.
    3) Finally, if they like the deal they can proceed with purchase.

Benefits for buyers.

    Saves time.
    Make purchases based on the price they are comfortable with.
    Get notification when somebody makes an offer.

Benefits for sellers.

    Sellers has buyer with money and intention to buy.
    Good for small businesses who do not have resources to buy ads and SEO experts.
    Get get notified when a new request comes in.

I am surprise giants like eBay and Amazon does have this. I would call it, name your price feature. Craigslist has something similar to this but not intuitive.