you should never skip school to go to work if you are sick. you think any one wants to be around you if you are contagious? hell no. do everyone a favor and stay home lest you get your whole crew sick.
In my last semester of college, I landed a full time "real world" job before graduating. I started to skip classes so I could go to work. $12.25 an hour was a TON of money to me at the time, and the advantages of going to work seemed to outweight the need to attend class.