I had a good experience buying 25FC and wanted to post in hopes others will report if they've been lucky as well.
1. Went to the "buy cash" tab in the game.
2. Chose 25 FC for $4.99, and chose to "pay with credits" (I didn't have any already).
3. Method of payment came up, and I chose PayPal.
4. Signed into PayPal and went though the normal PayPal process.
5. My account was charged $4.90 to purchase 49 FB credits that were automatically used to buy 25 FC (which is actually $.09 cheaper than the selection said).
6. Connected to the game and I had an added 25 FC and still no FB credits (which is good cause I didn't want any left over credits).
Luckily for me, it was as easy as when I purchased FC before the change and it saved me $.09 (won't buy much, but I like any savings

)
Hope I didn't just jinx my next purchase by posting a positive experience!