I have had two SBs in my lifetime and probably never again. My first SB was a UofA student, I wasn't looking but she was introduced to me as she was the roommate of a friend's SB. The girls needed help with rent, so my end of the bargain is to pay my SB's half of the rent plus a gift here or there. For that, I get to stay over one night a week, no weekends or exam nights. The girls like their Whyte Ave clubs, no saying hi outside of the apartment. That ended after a few months when both students returned home for summer, not sure if they returned next term and they never reached out.
Then through a website, I met a UofC grad student. This one went a little further, after a couple of months, it became an exclusive relationship; went for bloodtests together, and we celebrated the beginning of our restrictions free relationship in Banff. A lot less structured, evening dates, weekends in the mountains, she even insists on holding hands in public. It was a lot more expensive than the first one, not sure if it is worth it but was nice while it lasted. I knew she was close to graduating as she told me she was defending her thesis, then one day, she simply "disappeared". I did not even get a goodbye, she simply stopped returning texts. After that, I am not sure I will never do the SB thing again.
A good SB is a lot of investment, both $$$$ and emotions.