Need something to do web browsing, video watching, light photo and video editing and some programs like autodesk inventor. Nothing too expensive around $450-500, $550 max.
I suggest building PC around Pentium G4560.
Get 8GB of RAM;
Preferably an SSD;
No need for much expensive motherboard;
Be sure to get quality Power supply from tier 1 or 2 with the longer the better warranty, also no need for high wattage.