Yes, you do get what you pay for. BUT if you don't have the money, you don't have the money, right?
We were in your position a few months ago, but we found the money for these things. For DJs I would look on craigslist.com in your area. I found quite a few cheap ones there.
For photographers...
on (kinda messy...) or directly after your period. Ovulation is hard to pinpoint -- keep in mind that sperm can live inside you for a few days.
At the very least, use a condom and you won't have to worry so much! Pregnancy isn't the only thing you can "catch" by having sex...