Spending on Professional Development

I'm not willing to spend a ton of money on classes for professional development, especially as someone who isn't bringing a lot of coin to the family at the moment.

However, one opportunity arose recently that is literally 2 blocks away from my apartment. It's a two day seminar on advanced advocacy for $45. I bit the bullet and have decided to go, and more importantly, decided to spend the money. 

I think this is a tricky balance for people to figure out. How much can you budget for classes, development, connections? Do you think it's worth it? To what extent? 

I'm glad I have decided to go and really hoping to get something good out of it.

To find events, free or otherwise, I stay subscribed to my graduate school's listserve, and try to watch calendars at local universities or organizations I really like.