If you need to keep doing it, i suggest just buying a laser printer.
You can get them for about ~$100. It's more convenient because they're at your place. The printer comes with toner, once you use that, you can get toner off ebay for about $25 bucks and that prints ~2200 sheets (or so they say), compared to the same toner in the stores thats like $80 bucks.
That price of the printer ~120 works out to the price of printing about 2000 pages at officeworks (120/0.06). Looking back i can see that with all my uni stuff and VCE exams combined i easily printed more than 2000 at officeworks before i bought a printer.
Officeworks wants $0.06 a page and you have to go there and organise your files and all that. The toner is like $25 and will print 2200 pages apparently so 25/2200= 0.01 per page .
I reckon just buy a laser printer. I have a brother 2242D and got it from officeworks.
Before you go out and buy a printer check how much you can buy the ink/toner you need for it off ebay and check how many pages you can get out of it.