So, goals for your cube are:
1) Relatively cheap
2) Relatively simple mechanically

Yes?
Did a quick draft, here's some thoughts:
Keep in mind that when this sort of thing happens, it is often to the detriment of aggressive decks, as creatures tend to be a little weaker (which slows down games). This usually makes things like Day of Judgment and Oblivion Stone stronger than the norm.
Abyssal Nocturnous (gets bigger when the opponent discards cards) seems a tad out of place, as I've seen zero discard effects. Maybe get Stabwisker the Odious?
Board states can get confusing quickly when all the cards have relevant text. Consider cutting down on creatures with static effects, and replace them with vanilla counterparts or ones with ETB effects.

Murganda Petroglyphs seems really out of place, as there aren't many vanilla creatures.

There is a major glut of 3 drops in this cube. that is probably the biggest take home for me.

Skullcrack seems random

I'm mostly still at the adding 'acceptable' cards stage, not the removing the 'chaff' stage. I haven't yet added larger CMC dudes beyond iconics and a few I stumbled across while looking through some of the more recent sets, I also haven't done instant and sorcery spells yet other than those stumbled across while looking through recent sets or chosen from the start as rough balance markers or iconic spells I threw in because I thought I might want them.

Once I've finished adding stuff, I'll start trimming things. First I'll probably find the colors with the least stuff and trim the others' excess down to the same level, so that each color has an equal number of cards, then I'll only remove cards if I'm removing one from each color. I'll probably work it down to some relatively good number for a cube, something divisible by 360 probably, possibly down to 360 exactly, although that might be too little to get all the basics and variety I want out of it at that number.

http://cubetutor.com/cubedeck/138667

Way too many three-drops.

A big problem here is that all of the one drops suck and there aren't enough of them in any color that you want to be aggressive. Devoted Heroes aren't playable. They will be 15th picks every single time. Nobody wants a 1/2 for one because I'll just not care about it and play a real creature to block it.

You need development of archetypes. You want a mill sub-theme but there aren't enough enablers to get somebody there. Am I ever going to win with Laboratory Maniac? I somehow doubt it.

I also think the power level is not very balanced. There are some pretty powerful cards for limited in here but at the same time there are just dregs all over. Disparity between cards within individual draft decks as well as from pack to pack is going to be high and you're going to have a lot of inconsistent decks that don't do anything. On top of this there are way too many creatures. There are no removal spells so you're going to get into massive board stalls or somebody having a high variance creature that is just better than anything else that will end games on it's own.

I understand the simplicity theme and that's fine. But simple doesn't equate to bad cards.

As I said, I'm still in the phase of putting cards in, not taking them out. I'm basically still putting everything in that I find 'acceptable' while doing gatherer searches. And I still haven't gotten to instants and sorceries yet, nor the higher CMC stuff besides iconics and stuff I stumbled across looking at sets or simply knew early on I probably would want it. There will be much more removal once I go through the instants and sorceries on purpose of course. Then finish up the higher CMC stuff, then I'll start cutting stuff, and trying to equalize power levels and number of cards between colors and ensure good ratios between stuff for cube purposes.

Don't worry too much about getting the same advice twice. It is just stuff you need to keep in mind when adding and removing cards.

That said, don't hesitate to cut cards that you don't think will be working out.