Should I buy a 40GB PS3?

Ok first of all, I am about to buy a 40GB PS3 off of Ebay. (I live in Australia by the way)

It is quite well priced, and comes with all original boxing and manuals, and is only 2 months old and rarely used. I am worried about the warranty situation though. It has no purchase receipt with it, so obviously Sony will not honor my warranty. Is it likely to break down? (He has shown me it is in good working condition though)

Do you think I should just buy a brand new 80GB PS3? Although I probably do not have enough for one.

I always like to have the newest models, but is the 40GB PS3 still a good one to get? Is the only difference between it and the 80GB hard drive size?

Thanks.

I have a 40g ps3, it's fine, just make sure it's in working condition and also, is it brand new or a used one? Also the difference between the 80 and the 40 was backwards compatibility, meaning the 40g can NOT play ps2 games, but will play ps1 games, also less usb slots.

Yeah I am 100% sure it works, I have been there and tested it and it is in good condition.

I am just pondering between the 40GB and 80GB though. This console I am looking to buy was manufactured just 4 months ago also, so it is quite new.

Will Sony cover me with a warranty at all? Will they even repair it for me for a fee if it does break down? Or because I bought off Ebay will they refuse to repair it even if I pay?