I would try to get more doms.
The problem I foresee is the ability to obtain some of them. You should at least be able to get a Burial, since it is a starter dom, but I won't suggest more to you if you are trying to minimize cost.
The main problem you are going to have is that almost everything you use can be negated. If you run across a KoT, for example (used in a lot of meta for some reason), it will eat you up. On the flip side, there are a lot of interrupts/negates you will see attack your defense, and I don't know how well it'll hold up, not to mention FBTNB.
As far as going really cheap, it's not bad
Unfortunately it won't win to much at higher tournaments. Such is the nature of the meta