internal wall lining. what are the options?

I have a room under the house which has one brick wall and another made of bessar brick. The remaining two walls have large windows between brick pillars. I want to turn the room into something I can use as an office which means lining the walls. I could use gyprock but are there any better, cheaper alternatives that I could do myself that would still make the room look like an internal living area, rather than like an old storeroom? The brick pillars end 8" before the ceiling. The bessa bricks are painted white and are filthy. Cost is a factor.
Thanks in anticipation
Bunce

10mm plasterboard is something like $5 per sq m. I doubt you will find anything much cheaper than direct stick plaster.

Tools

what about pine lining ?......it can be stained a variety of colours to match the brickwork , and I would factor in insulation as well, your going to spend good money changing the look ....save some as well ....insulate the walls and save money on heating and cooling costs in the future :2tsup:

if you are capable of sticking ans setting gyprock, there is nothing cheaper. If however you would be getting a trade in to do it, then ply might be an option as it requires no setting B/C face 4mm ply battened out would be pretty cheap and easy to do.

Thank you all. Your comments indicate that it's not the materials I use that are necessarily the greater expense but the labour involved in having the job done. I'm a novice in all areas of building.
I do very much like the idea of pine lining. Thank you. I doubt I could successfully glue anything, so if I have to have it done by a tradesman anyway, I might as well have the best. Do I need a "specialist"? What tradesman would do a job like that?
Thank you all for your help
Bunce