i got a system about 6 months ago cost be about 550 all together, since then i have bought 2 brush heads, because i want to try different ones and a new pole becasue it was in a sale and spent 40 on resin,
i still have about the same no of custy, i am just finishing earlier giving me more time to enjoy my self
i think if you put 10 a week away in materials funds, this should more than cover and parts you might need to replace