Unlikely to be. The current best budget CPU is the G4560 but that would require a new motherboard and RAM. It sounds like you don't intend to go for a more substantial upgrade so this would be ruled out.
Seeing the i3-6100 is priced at $117 by Intel, and assuming that was the amount you were willing to spend, I don't believe anything fits into that budget. The only other way would be to buy secondhand on eBay or similar. Again, making sure the CPU is compatible with your motherboard.