Commuting to Brighton Sussex Medical School

I am planning on taking the train to and from the uni, which will cost around £12.50 each day. I live in Horley, and once I pass my driving test, I will most likely switch to driving to uni.
For those of you that travelled to Univeristy of Sussex or University of Brighton or BSMS by train, what was/is your method to getting there by train, i.e. buy tickets everyday, buy a season pass, tap with card, AND how much did it cost you roughly per month.

At the moment, with a 16-25 railcard, it works out at roughly £200 per month, excluding the price of a railcard per year (£30, or £70 per 3 years).