How good are slow fetches, especially if you don't have land-typed duals (i.e. the ridiculously expensive ones)? Wouldn't you be better off just with tapped duals? And there are better options than those - I suggest bouncelands and filter lands as good budget choices, but even Temples are better.
I would also include at least one basic of each type if only to give you fixing if you fancy/need it via ramp spells or basics-only fetches like your
Evolving Wilds/
Terramorphic Expanse (
Fabled Passage is apparently not that budget any more... I never buy cards, so I don't know). I don't think I like the Tainted lands when you have so few Swamps. Rather than fixing your mana, they might do the opposite.
On that note, isn't
Arcane Signet still cheap? I don't know what is or isn't budget, but I would evaluate your ramp options carefully if you want to optimise that a bit. I don't really like
Ghirapur Orrery - even if you're not able to use all of green's better, one-sided options, this doesn't do
much for you. On the one hand, Kenrith is a massive mana outlet so you're probably quite happy for everyone to ramp, but on the other hand you'll also never be without cards so the draw aspect might just help other people. I would rather use cards like
Collective Voyage,
Tempt with Discovery or, maybe even better,
Rootweaver Druid! These are also IMO just a bit more fun as they have a slight political angle.
A really funny card for Kenrith is
Tainted Remedy which gives you an alternative to
Sanguine Bond (I'm actually trying a non-Kenrith deck built around this card, but there aren't that many other ways to abuse it sadly).