This is best kept private if you're using the buying/selling one item method to grab prices.
I'll give you an item for example, let's say cannonballs.
Start buy price: 235, Start sell price: 245.
Bot 1: Buys for 235, Sells for 245.
Bot 2: Checks buy for 235, undercuts for 234, Sells for 244.
Bot 3: Repeat above.
Bot 4: RIP Margins.
You feel? :P