There are loads of post, where people talk about the transaction fee though. - But it's 0.05 as a default.
DISCLAIMER: I might be completely talking out of my ass, so take this info with a boulder of salt. From various bits and pieces of info, what i have gathered is that current settxfee works for normal tx in latest release 0.0.5 Also devs are testing setstakefee or some similar command for setting automatic ticket buying sstx fees. This should be available in next release. You can still use less fee by doing manual ticket purchase i think, as it uses the amount set by settxfee.
https://forum.decred.org/threads/ar...-current-price-4-55-dcr.840/page-4#post-12820 They already added it to the main github branch. You can download, compile and then set your own default fee increment and buy tickets. Or just wait till the next release is given out if you are too lazy to compile everything yourself.