If you don't need other training or certification classes, and actually are learning from your conferences, have your manager use her education budget to send you.
If she doesn't have an education budget, why the hell not? Their investment in you is probably large enough to warrant it, and they'd BETTER be budgeting for it, vs. throwing the occasional wad of cash out there. You're cheaper to train up to a new internal position than to find someone new and start from scratch.
Provided you're not going to the Shriner's convention for the water balloons and the little cars (unless you're in the water balloon or little car industry) education and conferences are normal, expected business expenses.
If you're in the US and the company won't send you, you can deduct your own purchase of the conference and associated costs from your taxes as "unreimbursed business expense" - BUT NOTE that there's a threshold that has to be met: I forget the number, but I think you can only deduct unreimbursed bix expense greater than 7% of your salary. So if you are $5 higher than that 7% mark, you deduct $5.00.
The begging thing might make your taxes complicated...