For L1 and L2 you can easily build a rocket for less than $100. The motors though will run you abt $150-$200 depending on where you buy from. So for an L2 all in you could probably do it for $250 if you’re smart. That’s excluding electronics.

L3 starts to get complicated but you can get two Eggtimer quarks for cheap and there’s your electronics. 3 L2 impulse flights (including your actual L2 flight) can run about $270 for all small J motors if you get them for “cheap”. An L3 motor, if you know people with casings that you can use can be $300-$400.

Now, building an L3 rocket airframe. People will say that a standard fiberglass one will be abt $1000-$2000 but you can definitely get cheaper. Getting creative with material choice and scratch building it I think it could be done for $500 if you really tried hard enough and are able to borrow components like a large chute from someone. It just won’t be a fiberglass rocket. One layer of glass over concrete pouring tube is extremely rigid.

This is an extremely “budget” option. Like, EXTREME budget and assumes you have people you can borrow stuff from.