But how do you know how much you can afford to pay for items? At most auctions, the items you buy aren't guaranteed to work, and since you're only buying one of whatever it is, there's a lot of work that goes into selling each individual item. You need to be sure there's enough of a profit margin for you to be profitable.

So what's a person to do?

Well, I've attended hundreds of auctions where my sole reason for attending was to buy items I could sell on eBay. My specialty was in surplus equipment – phones, networking equipment, fax machines, etc. – but I bought plenty of items that didn't fall into such neat categories as well. I learned a lot about how much I could actually afford to pay, and did it profitably for several years. Now I only go to auctions for entertainment and to buy the occasional item for personal use, so revealing the methods I used to you is no big deal to me, but it could be a great help to you.

First, check to see if the auction has a preview. If you see an ad and it doesn't say, call up the auctioneer and ask if there's anytime you can go to preview the items on sale at the auction. Most auctions have a bill of sale but I've found it's much better to be able to actually go see the items in person. You can get a good idea for the condition of the item and are able to note details about the items.

When you're previewing the items, make sure you have a notebook and a pen with you. You're going to need to take a lot of notes. Your job is to identify anything you think you could sell on eBay for more than $20 – less than $20 and it's probably not worth your time. If you're not sure, write it down just in case. Take specific notes of model numbers and the condition the item appears to be in.

Once you've noted everything you think is worth more than $20, you can return to your home. Now it's time to hop on eBay and do some research. Start typing in the items and find out how much other sellers are getting for their items – use the completed items search. Find what a middle of the road price is for the item and right it down next to the item. Now you know how much the items are worth.

If an item sells for $90, then you can afford to pay up to $80, right?

Well, if you sell on eBay for entertainment purposes, sure. If you actually want to make some of that green stuff commonly called money, then no.

My goal was always to buy the item for 50% of what I could sell it for. Does that seem low? Well, most auctions aren't willing to guarantee that anything will work, and a lot of times you don't even know for sure if the item was working last time it was used. I've bought plenty of items that looked like they'd work and got them home only to find they were junk. So just know that some items will not work, and you'll have to take a loss on them. Since you want to make money, you'll find that 50% is a good number to have in mind. Now the 50% is a guideline, not a rule, so if you find an item and want to go higher, that's fine, just keep in mind 50% as your goal.

What if preview is immediately before auction or there's no preview available? Well, this is where you're going to need to take advantage of technology or a friend if you're new at this. When you get there, find out what items the auctioneer will start with and write down the first few items that you think would meet your requirements and write them down on your pad. Now either pickup the phone and call your friend who can look these items up for you or use your phone as a modem for your laptop and look them up yourself. If you have a web enabled phone, you can use that as well.

Now don't be disappointed if you don't get most of the stuff you want. Some auctions, that'll happen. Other auctions, you'll get most of the items you wanted. There are ups and downs like any business, but over time it all evens out.

Happy Bidding.