I have yet to pay for credits, I get them through surveys and other free credit methods.
Surveys are hit and miss. It is hard to qaulify for them sometimes...so be patient if you do them.
Keep an eye on the fre credit offers they make on the earn free
credit page. There are some good ones out there. If you know you are
going to buy something, check to see if you can get credits for it.
One example...I trieds the free netflix trial for 30 days and got a
bunch of credits. Before the 30 day trial ran out, I just cancelled the
subcription. No big deal.
Bottom line.. there are lots of opportunities for free credits if you are patient and willingto put the work in. Or, you can just buy them :)
MustangLarry