Have a model transparent for one player?

I want to have it when some player clicks buy on a SurfaceGui. When the player clicks it, if they have enough coins to buy it then the Model becomes Transparent and CanCollide becomes false, but only for that one player. This is what I have so far, but I don't know how to do the transparent and the canCollide thing:

script.Parent.MouseButton1Down:Connect(function(plr)
	local coins = plr.leaderstats.Coins
	local price = script.Parent.Parent.Parent.Price
	if coins.Value >= price.Value then
		coins.Value = coins.Value - price.Value
	end
end)

This script is a normal script.

The model is in workspace, in a folder "Levels", in a model "Farm1", and the model I want to have transparent and canCollide false is in that model. The models name is "Doorway".

Use a local script for this. but local scripts cannot work if they are a descendant of workspace (meaning it's a part of workspace, doesn't matter if it's in a folder of workspace), but instead of using script.Parent, you'll have to locate the path like this: workspace.Blah.Blah.MouseButton1Down, since it's a local script, all effects will not replicate to the server (expect if it's an animation, that will show to everyone), now, loop through the children of the model like the following:

for i,v in pairs(Model:GetChildren()) do
	
end

Now, check if the child is a Part, Union, MeshPart etc like this

for i,v in pairs(Model:GetChildren()) do
	if v:IsA("BasePart") then
		
	end
end

Now all we have to do is make it transparent

for i,v in pairs(Model:GetChildren()) do
	if v:IsA("BasePart") then
		v.Transparency = 1
	end
end