I certainly can't afford to replace it, that's for sure!
Perhaps you can...
I just bought some big wheelie bins from here:
http://www.britishbins.co.uk/off-stock-seconds-lidless/660 ltr capacity bins are only £78 including delivery, and seem sturdy to me. They do have a drain hole in the bottom, but come with a plug. I'm planning on burying mine, which I'm hoping should prevent both splitting and the plug being forced out. The plug does stick out a bit, and you will have to remove the wheels (easily done with a 10 mm spanner), but that will mean that you have to at least recess the surface you are putting it on to prevent the bin rocking on the plug and damaging it - burying it (at least partially) seems to me to be the best solution.
It may be that the UV in sunlight has weakened the plastic, resulting in the split. Burying it should prevent this too.
I should also add that there are a total of 10 x 8.5 mm diameter holes towards the top of the bin that will need to be sealed, so I've ordered some M8 bolts, nuts, and rubber washers to make them water tight. It cost me just over £10 including postage for enough bolts/nuts/washers from ebay to seal 2 bins with some left over. You will also need a T30 "star" type security key to remove the bolts that are already occupying the holes.
On top of that I would suggest 4-6 bags (I'd estimate) of sand to put in the bottom of the hole you dig if you want to bury it, and around the sides to support the bin, as well as allow for the plug at the bottom of the bin. I've measured the walls of the bin at 5.5 mm thick, so not sure how necessary the sand is, but it seems like a good precaution to take.
Oops - I just noticed that 6 of the 10 holes that need sealing are just under 7mm diameter, so require M6 size nuts/bolts/washers. Don't know how I missed that! You could probably get away with M6 for sealing all the holes rather than having to buy both M6 and M8.