Hi, I'm a freelance illustrator who's on the hunt for more work as well! I don't know if it's allowed to plug other forums (fora?) here, but the AOI has a forum that is worth a read through as there is lots of advice about self-promotion, agents and the like.
Basically, though, I have built up a contacts list and just keep sending out mail-outs to them, either postal or email. My main target is picture books, so my list is mainly children's publishers and magazines.
Also, not having a degree shouldn't be any obstacle. Lots of illustrators don't (I do, but I needed it because I needed the kick up the arse to help me change career).
As for affording an agent, if they're asking you to pay up front, I'd be a bit suspicious. Agents who belong to the Society of Artists Agents should be reputable, but not all reputable agents belong to the society, if you get me.
My thought on doing low-paid work: probably best to try not to. I know how tempting it is because I've done it. It just gets to be a resentment-fueled pain in the bum for not much money.
Hi to the other illustrators on here too!