The difference between a basement people visit and a basement people live in is a bathroom, and the difference between a rec room and the place everyone watches the game is thirty inches of bar sink.
Basement baths run on gravity's terms. If your builder stubbed a rough-in into the slab (common across Fishers builds after ~2000, look for capped pipes in an odd corner), you have won the lottery: the expensive trenching is done and a full bath becomes a straightforward build-out. No rough-in? An up-flush ejector system or saw-cut trenching gets it done, we price both honestly, and the ejector route has gotten quiet, reliable and code-clean.
What we insist on either way: proper venting (not the "cheater valve and hope" method), a fan ducted outdoors, waterproof board in wet zones, and tile or LVP that treats the slab like the slab it is. A basement bath built right feels exactly like an upstairs bath, that is the test.
Plumbing rooms anchor the whole layout, so they get placed first, near existing stacks when possible, back-to-back with the bar to share wet walls and save real money. Budget-wise: a rough-in bath build-out typically runs $12,000–$20,000; ejector-based or trenched baths add to that; wet bars run $5,000–$15,000 from essentials to showpiece. Each carries its own line on the itemized quote, so the bar can flex while the bath stays sacred, or vice versa.