I would just wait until you save enough and get a decent laptop, or one that could run maya with no probs, if you opt for a budget one you will be pi$$ed off when it comes to rendering even panning around your model if you do decide to have a busy scene. I held back and bought an alienware, ok it cost like £2000 but is well worth it I no longer get that feeling of wanting to skim the mouse the length of the room when its 'stuttering' as it runs ever so fluid now.

Ps Stay away from ebay it's not worth the hassle.