Some Bluetooth dongles have decent range, but usually not as good as 802.11 wireless.
I would go ahead and spend the extra money, mainly because the bandwidth of WiFi is a lot higher, so printing should be faster and more reliable.
...so long as you're sure the WiFi print server is Mac compatible. I just got an Airport Extreme Base Station, but HP has not updated the driver for my all-in-one for Panther yet! argh.
CC