People have reported purchasing LEGO Marvel Super Heroes Electro (5002125) from their local Toys R Us store. This is the movie version of Electro from The Amazing Spider-Man 2. There’s a future planned promotion for this set but you can purchase it now for $3.99 at the store.
If you don’t see it on the shelf ask an employee to look up “R”Web#: 238428 or UPC/EAN/ISBN: 673419221863 on their computer. A likely place they are storing them is in the cabinets at the customer service desk.
If you can’t manage to get a hold of the minifigure locally, the prices on eBay have come down a lot lately as more people are able to find this set.