Buying a 125 Motorbike via Gumtree safe?

I've had a 125 before and just going to get a faster 125 since I have a Chinese slow 'dirt' bike.
I live near London, so most bikes around are expensive to buy, and the further distance away seems to just get cheaper, maybe because the lack of population in certain parts of the country?
Anyways, I'm looking at an Yamaha YZF-R125 or an Aprilia RS 125. I've found a few just below the £1000 mark.
When looking at the details, they state nothing is wrong with the engine etc or they may have dropped it and broke a few panels scratched a few things hence the low price.
I want to buy one from Gumtree, then get uShip to deliver it back here, I'm also going to ask them to take a quick iPhone video or film them just starting the bike up, giving it a rev and the show a closer look of the bike.

Do you think this is safe or is it still to risky?
I don't mind receiving it and there being little damages, since these bikes up north in scotland or wales are around £1200 cheaper than ones around my area + it's only around £75 - £150 shipping.
And also, I only have a part time job because I study at Uni, and I don't get much, it'd take me ages to be able to afford one around my area since I've got so many other things to pay for

I don't know what GumTrees policy is on returns like compared to Ebay's. Could be risky.