How to get a PSA 10 for nearly the price of a raw card
A little sidenote beforehand: This is a risky strategy, so be careful.

Anyone heard of GMA? No? Well, you are not the only one. GMA is a grading company based in Florida, that does grading for 4 bucks a card. They are the lesser known grading companies besides PSA, BGS and SGC.
You can buy GMA 10 graded cards for nearly the price of raw cards on eBay.
You want to see an example?
2011 Topps Update #175 Mike Trout RC
GMA 10
USD 1.000
RAW
USD 900
PSA 10
USD 2.500

Nevertheless, they are also applying certain quality standards for grading, which means that you can use them as some kind of “pre-selector” to understand, if the card is authentic and meets certain quality standards.
So here´s the deal:
Buy GMA 10s of your selected player, crack the case and submit it to PSA for grading. If you don’t want to crack the case, you can also submit to PSA and ask them for a crossover. Please note that your chances are higher, if you crack the case, since PSA may be feels a little underwhelmed by having to crossover from a GMA 10.
By doing so, you reduce the risk of buying a raw card that has some potential flaws, which most probably would only get you a PSA 8 or 10. Also by doing so, you can dramatically increase your chances of getting a PSA 10, since it is nearly impossible to understand the condition of a card just from mostly sloppy taken eBay photos of raw cards.