I haven't had any problems with buying with Google. This includes buying apps and products linked with Google.
One thing to add; if you don't like the app, and you uninstall within 24 hours, you'll be able to get a refund. If it's over 24 hours (or if you try to reinstall within the 24 hour period) you won't be able to get a refund, but if you decide to reinstall it you won't have to pay again.