If you're a one-person shop and you want to just do the live paypal version and reverse it all, I think Dr.Byte is right. But don't forget to reverse it! And I hope you use your own accounts!
Good reasons (in my mind) to take the time to set up the paypal sandbox are:
- the credit card fees
- the time it takes to reverse transactions and
- the cost if one forgets or does not get around to doing it because a test script dies or something.
All together, including the time it took to track down the problem above it took me about 3 hours to sign-up, learn about, configure, trouble-shoot and then successfully run my first test using the paypal sandbox. Tracking and resolving the problem took about 2 hours -- 45 minutes of which was spent writing the above post so others wouldn't have to spend that time.
But if you're a store for a large business with multiple developers and testers that needs to test lots of multi-thousand dollar transactions, the credit card transaction fees are quite hefty if one forgets or does not get around to canceling the transactions in a live environment. The first test I did, using the paypal sandbox, of course, cost $29.90 in credit card fees. That's using paypal's best rate (2.2% on a $1,018.00 purchase. We need to test our store against $700 to $8000 purchases. I want the peace of mind knowing that I don't have to stay on top of making sure that anyone who does a test also reverses the charges. Even for my own one person store, it's great to not have to think about it.