Tok - Your detect magic confirms that the items are indeed magical. The magic in the wand is evocation, which aligns with his claims about it being a wand of magic missiles and the magic within the stone is conjuration, which aligns with what you know about the teleport spell. The few mushrooms you inspected were each of varying schools of magic, but given that the effect is random, you aren't surprised.

To the rest of the party: These check out as best as I can tell. Unfortunately I don't have funds for more than a few mushrooms

Tok will pay 2sp for 2 mushrooms. Aiming for evocation ones if he can.

I'm willing to chip in the little gold I have (4gp) if anyone is short though

I’ll pass me thinks. Not one for eatin’ weird food, and the items are too expensive fer me now

Kor eyes the mushrooms warily, trying to decide if they're good or not. She remembers nights when she ate bad ones.

Nature 15

Tok - The man takes your coin and lets you pick the mushrooms you want. You're fairly confident you picked two of the evocation magic mushrooms.

Kor - You recognize the mushrooms as morels, though they aren't typically purple in color, you're confident that they are safe to consume from a strictly natural standpoint. You can't speak for the safety of whatever magic has turned it purple though.

Kor & Doc -

Kor grasps the handle of her greataxe as she motions to the group. "It seems we may have company..." With a flash, her axe swings into the air as she fully brandishes it. "The unpleasant kind."

If there is time Felmar would like to load his crossbow and have it at the ready for whatever is coming 

All - You all hear a growling and chittering sound coming from a violently shaking group of bushes nearby. The elven man takes a step back and gasps when Kor draws her greataxe, "I realize my wares are not for everyone, I will be going n- Aaaaarrrggghhhh!" Something bursts from the bushes and charges at the elven man. It appears to be a very dirty halfling man. His clothes are muddy and ripped and his hair sticks out wildly in all directions. Purple foam flies from his mouth as he howls, and you see what appears to be purple vomit covering the front of his shirt. The crazed halfling tackles the elven man and begins clawing and biting him with all the ferocity of a starved owlbear. The elven man screams and thrashes beneath the halfling, "Help! HELP! Oh gods, somebody HELP!"

I’m bettin’ THAT’s what happens when ye eat those mushrooms. Kor, NOW is the time fer restrainin’ somethin’! Grab that lil guy and try’en hold em tight. And watch those teeth!

Felmar takes aim with his crossbow but holds fire to see if Kor can successfully grapple the Halfling. 

Doc speaks to the trader in Elvish “you wouldn’t happen to have any healing positions would you? And with these brutes I may have need for the stone. Though thirty seems a tad high?”

"The horse was just practice!" She yells. Kor runs up to the crazed Halfling and attempts to pull him away.

Grappling 9

All - Halfling STR check: 14

All - The halfling continues to savage the man, biting down hard on his arm as Kor tries to pull him away. The man wails in pain, "Stop! STOP! OW OW OW!"

Tok looks on in horror at the halfling's vicious attack. When it brushes off the giant Kor it's clear this won't be easily resolved.

Tok intends to attack the halfling. If we need initiative: 10

If not, he will cast Frostbite. Halfling will need to make a DC 13 Con Save or take 4 cold damage and have disadvantage on it's next weapon attack roll (since most monster bites are considered weapon attacks, I'd contend that his would count, but up to you)

Felmar has had enough. He draws his warhammer, Squelch, and takes a swing at the Halfling with the intent to knock him unconscious, or at least draw him away from the other guy. If we need initiative, I got a 4

Target: Crazed Halfling

Attack: 11

Damage: 10 Bludgeoning 

Tok & Felmar - You watch as the crazed halfling's body becomes covered in frost and its vomit stained clothing stiffen as it freezes, restricting its ability to attack the now weeping elven man. Felmar's warhammer catches the halfling neatly in its side, launching it off the man and into the road where it rolls a few times in the dirt and stops. After a few moments, the halfling doesn't move. The purple robed elf is still curled in a fetal position on the ground, sobbing. The man's sack of mushrooms was ripped in the attack, scattering them across the road.

Tie him up! Felmar said pointing to the Halfling. Then he goes to begin examining the salesman

Medicine: 10

Felmar - Aside from a few scratches and bites, the elven man appears fine. He sits in the road with teary eyes, sniffling and trying to knock the dust from his robes, "I-It just attacked me!" He looks at his wares scattered across the road and moans, "Gods, why me?"

Quit your belly-achin’ man! Ye’ll live to whine another day.  Don’t go anywhere, we ain’t done talk in’. Doc or Kor, could one o’ ye keep our friend company? Tok, can ye help me check out the wee one? Might need a magical eye.

Felmar goes over to the unconscious Halfling and begins examining him, trying to determine what caused his aggressive behavior.

Medicine?: 3 🤣

This is a... new one for me, but I'll see if I can help

Tok will do what he can to discern what's wrong with the halfling with Detect Magic and Arcana: 7