Re: indoor shooting range in your basement ?
The cost alone, without consideration of space, etc. is UNGODLY if done properly, even if it is just a personal, non-public range (start thinking about costs for materials/supplies/construction of a backstop whether wet or dry, lead/contaminant removal, a target system whether manual or mechanical, etc.). Then consider the HVAC system (and assoc. costs alone) could feed a small family for many years and without adequate ventilation, you get the priviledge of inhaling contaminants like lead, sulfur dioxide, carbon monoxide, etc. which not only have an immediate adverse effect, but can build up over time creating an even more unsafe environment. The legal issues are a whole different ballgame and one that you will need professional assistance to contend with. Also, don't forget zoning, local, state and federal law pertaining to the project before undertaking anything other than daydreaming.
If you are serious, try running a Google search and reading some online narratives re: indoor range construction/budgets. Also, the NRA has a sourcebook re: range construction...a part of it deals specifically with indoor ranges. If you get serious, I'd start there and plan for a long and expensive road ahead.