Are iphones always on contract?

I'm thinking of buying an iphone 3 from ebay. It says its locked to Vodafone. Does this mean its pay as you go or what?
sorry if this is a stupid question I was just wondering

thanks

Added (1). But this one of ebay that i'm looking at is quite cheap, and locked to Vodafone… Does that mean its pay as you go?

Not a stupid question.

It can be either prepaid or on contract, but only with Vodafone

Either pay as you go or contract, aslong as it's on vodaphone. I'd say with an iPhone go on contract, they use a lot of internet and you can probably get a deal with unlimited internet for about £12 a month, where as on pay as you go you'll be spending way too much on internet usage

There's no iPhone 3. 3G/3GS.

It being locked to Vodafone means it will only accept Vodafone SIM cards. Doesn't state if it is on pre-paid or post-paid. More like likely post-paid though.

But to answer another question, no iPhones are not always on contract. I bought my last 2 iPhones off-contract, and unlocked.

It just means currently you can only buy a phone plan (pay as you go or contract) from Vodafone. You can get your phone unlocked from certain phone shops or even at the market so it can operate on any network. I got mine unlocked for £5 a few years ago.

I would say though that iPhone 3's do have limited capability with regard to apps and software. Some apps won't run on any iPhone older than a iPhone 4 and he new iOS 7 update won't run on it either. Not that this will be a massive problem it just depends on what you want your phone to be able to do really.

Hope this helps