RE: Tamiya flash unit
Upgrades are just that. You can do as many or as few as you want. HL tanks can be brought up to battle ready status for under $300 as a guesstimate. You don't need to have metal tracks and all the fancy do da's unless you want them. Keep reading the posts and ask questions of things your not sure of. Plenty of experienced guys on here to help you get your tank to where you want it.
Herman