Can i take any legal action against these people?

Although this is a small dispute monetarily, it raises some complicated issues.  In New York, there is an implied covenant against the seller of a business impairing the goodwill that he/she/it has sold, which generally means soliciting the same customers.  This covenant can be limited by express agreement, but in the absence of any agreement to the contrary, which seems to be the situation here, you may have a claim that the other vendors have breached that covenant by setting up a competing stall at the same market as the stall they sold back to you. There are many issues with this claim, however.  First, did they sell you any goodwill?  The transaction you describe sounds more like rescinding the original sale than entering into a new sale.  Also, you yourself said that the stall could be moved anywhere, so was there really any goodwill in the first place?  Also, the same covenant could apply to you.  The other side will claim that you breached the covenant by operating your bottled juice stall in the same market.  I don't think this is true, because you were already operating that stall before the sale, and therefore couldn't have been impairing any goodwill the smoothie stall had. Moreover, the other side's activities may not violate the covenant, which doesn't preclude competition, just solicitation (it's a little more complicated, but basically that's it.)  If I sell all the assets of a business to you, I can open a competing business, but I can't send out flyers to my old customers asking them to do business with me instead of you.  I'm not sure that opening a competing stall in the same market violates the covenant. Bottom line, you have a claim, but it's no slam dunk.