Makes sense, if you think about it. Probably chopped in against something else, tyres were low so needed changing, might as well put the cheapest things on to maintain profit margin on the basis the buyer is very likely not to be an enthusiast, as enthusiasts don't buy the 2.7L version.
Depends what was on there before too, might've been used Linglongs on the back and 040s on the front!
Ironically all they've done is given me a huge thing to barter over when buying it. Not that I'd buy that, but you know what I mean.