Hi Ms Binki:
First, please understand that bidding "blind" is exactly how almost everyone (I say almost because there are a few exceptions) purchases a home. As Terri mentioned below, unless the seller instructs the agent to give the information out regarding pricing, there is absolutely no way for you to know who is making offers and how much money they've proposed to the seller. I know it's frustrating, but, until the home actually closes escrow, none of us (Realtors and agents included) will ever know the actual home's sale price or the range of prices that were offered by all the buyers.
The only way that you'd be provided with information about the pricing is if the seller instructs it (and most would never opt to do this) OR you're in an auction. And remember, sellers are not conducting auctions, they're conducting sales in which the market sets the price of the home and the highest price (usually) gets the home.
So the best thing you can do for yourself, is to look at your finances and the desirability of the home and make your highest and best offer to the seller. This is not an auction and you are not obligated in any way to keep pumping up the prices beyond what you can reasonably afford or what you're comfortable paying. This will mean--especially now when home prices are still rising--that sometimes you don't get the home or can't afford the final price of the home, but that simply means it will take more time and more offers, but NOT that this is an impossible situation.
Good luck to you! Make an offer you can afford and feel comfortable making and I wish you the best!
Allison James Estates & Homes