Hi Ashley,
Finding a product with a high profit margin usually means finding a niche market.
We have recently come up with a few searches of our own here at SaleHoo with the help of our Market Research Labs.
Here are some niches that had a good chance of success:
1. Slimming Pills
2. Men's Underwear
3. Building Blocks
Here are the links to some of the blogs that we have come up with to present the actual data from these niches coming off eBay:
Link hidden: Login to viewLink hidden: Login to viewLink hidden: Login to viewOne of the best ways you can also start doing this is just by selling some stuff from around the house that you no longer need any more. In the process, you will often stumble across items that sell really well that you would never have otherwise picked!
Good luck :)