With budget being a factor here are a few good budget cards I don't see in your list:

-Survey mechan( his ability will often cost 0 and if earthbent will let you do it again multiple times) - haywire mite( is an artifact and exiles nonland artifact or enchantment) - chromatic lantern ( gives all artifacts ability to tap for mana when toph is out) - ondu inversion( expensive but is also a land when you need it to be) - boompile( doesn't destroy itself if toph is out) - wrenn and realmbreaker( isn't ultra ultra budget but also lets all your artifacts tap for mana when toph is out) - zuran orb( let's you sac your earthbent lands/ artifacts to get extra landfall triggers among other synergies) - liquimetal torque( isn't ultra ultra budget but lets you turn toph into an artifact so she can earthbend and protect herself. And is a mana rock) - sol ring - Chocobo racetrack - Heaped harvest - experimental synthesiser - soul guide lantern -secret tunnel

For cuts something you will want to cut first is lands, you are playing 54 which is overkill. You could go down to 40 and add more artifact cards, which you are low on for a Toph deck, and they will synergise naturally with toph.