At the start I'll note that I'll do my able best to keep it budget friendly.
I'm seeing one glaring issue here and that's with Jace's Phantasm. I get that it's a one-drop 1/1 flyer with the potential for getting a LOT bigger, but you should probably build in at least a little bit more of a mechanism for getting to those 10 cards in the graveyard than Mindshrieker. Trepanation Blade is one option as each attack could rip 3-5 cards off and you're at 10 faster than you think. Thought Scour is a definite highlight here as it can help give you card advantage while also causing them to drop cards. Mind Sculpt doesn't really fit your strategy as cleanly, but can be a nasty thorn in someone's side AND would get the Phantasm's to that point much faster.
Alternately, you could simply slide out both the Phantasm and Mindshrieker for some other low cost flyers - I'm thinking War Falcon (which works with your Lyev Skyknights), Aven Squire for the early game exalted bonus, Arctic Aven (as lifelink is HUGE against the flood of aggro right now), or even Drogskol Captain who would have an even larger benefit by pumping your spirit tokens and giving them hexproof. (Note that none of those options top 60 cents per card!).
Beyond that, unless you're running the Captains, this deck has one giant weakness - which it actually has one of ironically - Detention Sphere. Despite all the fun spirits you can pump out with Midnight Haunting and Lingering Souls they could all be cleared out by a single detention sphere. For things like Electrickery and Mizzium Mortars I would consider running Rootborn Defenses in the maindeck as it can prove to be one hell of a combat trick that also produces more spirit tokens for you.
Beyond that, I can see where, without added pumping for him, Geist of Saint Traft really wouldn't be as effective as you like. Jace does a lot more for this build giving you both some protection and some card advantage.
In either event, you're likely looking at $3-$5 and this could potentially be something fun and perhaps even competitive.
On a side note, if you wanted another fun budget-friendly play, splash a bit of green to put in Bower Passage, which, for two will make all your creatures completely unblockable.