Help me buy books and supplies for university

Hello, I'm an electronics engineering student from Costa Rica, I am an asperger and I'm in my fourth year of university and need help to buy books and supplies for this semester.

Many of the books I need are not avaiable in the university's library or are not enough for the number of students who need them (for example there a 5 books for 70 or more students enrolled in an specific course). Many of the books I need are relaatively affordable here, an average of $50 to $100 but some of them are not even available in my country so I have to order them to United States where are a lot expensive and I have to add the shipping and taxes from my country.

As for supplies, many of the laboratory courses I take require electronic components, most of them are cheap like resistors, capacitors, etc, but some are more expensive like sensors, motors or boards. I haven't able to buy a multimeter, somketimes I borrow one from my partners but I can't take them to my house where I could spent more time studying and learning in a practical way.

I sometimes give private lessons to other students (differential equations, advance calculus) for financial help but many of them only look for help around 2 weeks before the end of the semester. I'm also saving money for a new laptop since my current one has almost 6 years and many of the software we use in university is getting heavier to handle by my laptop and sometimes it crashes in the middle of a simulation or synthesis.

Thank you very much for your help and time.