Okay, so I finally decided to sign up for PSN+ ($18 isn't that bad and there are some other extras that will make up for the price, not even including the MK9 demo).
Anyway, last night I logged into my PSN account (from my PC) and went to add funds to my wallet. Since I already had a little over $3 in my wallet, I only needed to add $15. PSN gives you the option to add $5, $10, $25, $50 and $150 (or the amount plus what you have in your wallet already that will add up to $150). Since I only needed $15, I realized I'd need to make 2 transactions (I don't use PSN that much, so I wasn't completely aware that you could have PSN automatically deduct the exact cost of whatever you buy directly from your credit card... more on that in a minute).
So first, I purchased $5. That went off without a hitch and it was added to my wallet. I went back to add the remaining $10 and be on my way to a fresh, 3-month PSN+ subscription (and, subsequently, early access to the MK9 demo!). I selected the $10 option, clicked to add it and then got a message that my 'credit card information was invalid'. Huh? I went back and tried again.... same message. I tried re-entering my CC info, but still nothing. I then noticed the option for the automatic payment. I configured my account for this and booted up the ol' PS3. I selected the PSN+ subscription, it said it would charge me $9 and change and I clicked purchase.... ERROR. What the hell? My final attempt was to add a totally different credit card to my PSN account and, you guessed it, got the same errors.
To say the least, I'm not very happy. Anyone else face this dilemma? I guess I could pick up a PSN card at the store and add the funds that way, but I'm afraid I'll do that and then get another error and be left with a worthless card. It's starting to look like I should have stuck with my instinct and waited until the 15th to get the demo for free. :-(