Hello my name is ***** ***** certified computer professional with over 10 years experience. I will be happy to help you.
For laptop parts I use this site http://www.sparepartswarehouse.com/Toshiba,Satellite,S75t,PSKNAU-008004,Laptop,System-Boards.aspx
That link is for your model it costs $282
The processor here http://www.sparepartswarehouse.com/Toshiba,Satellite,S75t,PSKNAU-008004,Laptop,Processors-CPU.aspx looks yo run about $25.
Your best bet though is to give them a call at 1-***-***-**** to confirm you are getting the correct parts as they can vary by model so usually you need to pull them out first and make sure you are getting the right one.
If you need more help please let me know. Also when you have a second please take a moment to click the stars above, 3 or more stars please to acknowledge I provided you with an answer/advice. You can reply back at any time if you have any follow up questions.