It might be good to think of the reasons why you're busy and see what you can do about that. Otherwise, think of very small pieces you can make in a short period of time. Just do a bunch of those rather than one long project that may not get finished. Time management and discipline to set aside time could also work.
If you're not getting offered union jobs then I don't think it's the right time to join. It might be best to wait a bit--you'll probably know when it's the right time. At a certain point it may be a good idea to join, but if you aren't getting union work then you're paying unnecessary costs.
I agree with Carlo in that it's better to spend a bit extra and get a filter that doesn't degrade the image. The best value for money would probably be a variable ND, so that you can dial in the exact amount.
However, getting a few solid NDs would be good for quality. Maybe in two stop increments such as: .6, 1.2, 1.8, 2.4
Those are probably the ones you would need and could adjust the rest with ISO and small aperture adjustments.
The Firecrests are really good if you're looking for great quality.
This was basically posted five days ago: http://nofilmschool.com/2017/07/watch-12-trademarks-youll-see-pretty-muc...
I second what Michael says on the minor thing. You should focus on creating your own opportunities--making short films, maybe trying to do some event work (might not be exciting but it pays better than shorts and also helps you become more reactive to situations) or seeing what else is possible in your area. Other than that, you could research how to become a good PA so that when the opportunity to be one arrives, you can make a superb impression.
Not really anything in there that I'm interested in, but it's a good deal even if there's only a couple of items you want. So it's a good discount but only if you think you have something to gain from it.