if statement with multiple conditions, is my script correct?

So, im trying to make an if statements with multiple conditions. for example, if you have more than 10 rebirths but less than 30 then it would give you a different cost.

function Rebirth4(plr)
	local Clicks = plr:WaitForChild("leaderstats").Clicks
	local Rebirths = plr:WaitForChild("leaderstats").Rebirths
	local Cost1 = plr:FindFirstChild("Cost1")
	local cost = plr:FindFirstChild("Cost")

	if Clicks.Value >= Cost1.Value and Rebirths.Value <= 10 then
	cost.Value = cost.Value + 100 --  cost multipliers
	Cost1.Value = Cost1.Value + 250 -- cost multipliers
	Clicks.Value = 0
	Rebirths.Value = Rebirths.Value + 4
	
	elseif Clicks.Value >= Cost1.Value and Rebirths.Value >= 10 and Rebirths.Value <= 30 then
	cost.Value = cost.Value + 1000
	Cost1.Value = Cost1.Value + 3000
	Clicks.Value = 0
	Rebirths.Value = Rebirths.Value + 4