I switched to Acuvue Oasis (one pair per week, wearing them day and night, no solution), they are composed of a slightly larger (quaternary) molecular structure, thus allowing a greater rate of O2 diffusion (99% as opposed to 90ish%) through the lens to your cornea. My eyes have actually improved since wearing these lenses (health wise) according to my optometrist, so i'm more than happy with the results, especially the total lack of dryness, even on 11hr+ days. They also seem to have elliminated the tired feeling brought about by wearing monthly's towards the end of the wearing period. Think i was on Proclear before.
Experiment is probably the best idea, your optometrist or local optician can supply you with testers, and also advise you upon any government healthcare plans that may apply to you as i'm sure this could have a bearing if it means saving you $50 a month. Good luck, sure that you'll be fine!