CPU&Mobo using ddr3 under 300$

[shoop da whoop]

Hey i was wondering if someone could help, im looking to “upgrade” my cpu and mobo but while still using my 16 Gb of ddr3 ram? If its possible. I only have a budget of 300$ as its for christmas im pretty decent with hardware just looking for any other opinions.

 

[fredfinks]

ebay. 4th gen series intel.
e.g. i5-4670