Best option in that case buddy is to buy second hand.
The best on the market can be had for £50 second hand and the cheapest can be picked up for a tenner sometimes. The forums classified is brilliant for this.
Masks are personal though...trying before buying is highly recommended. If you have a paintball shop near you then pop in and have a word. Try on the gear and see what you like. If you say you want something cheap they will be able to advise some products and you will be able to try them on too.
If you don't like the mask you end up buying...you might as well have used a rental one for free.
I won't give any actual recommendations of specific products purely because I can't. I've only ever used expensive ones which wouldn't be advisable if you only play once every 4-6 months.