Lower power version of ULN2803?
ULN2003A are usually quite a bit cheaper, but only 7 channels. 

BTW, they're not really good for 500mA, if you read the datasheet critically, you'll see it's more like 50 or 60mA per channel with all channels active, assuming a reasonable temperature range. 

From the Toshiba datasheet, the lower graph is for Ta = 85°C