7–9 Months: What This Month Costs, What to Buy, What to SkipModel month ~$205/mo model · about 8 diaper changes a day · 24 oz formula/day model, solids rising. All prices are model examples — run your real numbers in the simulator.
Solids redraw the bill: formula ounces ease, baby food appears, wipes work overtime on hands, faces and highchairs. Crawling changes the diaper game — fit and fastening speed start beating pure unit price for daytime changes.
Model month at 7–9 Months
■ Diapers — $58 ■ Feeding (formula model) — varies by family ■ Wipes & basics — $39
Feeding is shown at a formula-model level for scale; breastfed and combo-fed months sit lower on that segment only. Everything else is stubbornly similar — babies are egalitarian that way.
Buy (this stage earns it)
Run the hybrid food system: batch cubes + deliberate pouch reserve.
Trial pull-ons for daytime if changes have become wrestling matches.
Re-price wipes by cost-per-change — mess volume just changed the math.
Baby-proofing basics (gates, outlet covers) — buy the plain versions; they are safety gear, not décor.
What one day of diapers costs at 7–9 Months, by unit price
Store brand, 17¢$1.36/day
Mid-range, 24¢$1.92/day
Small packs, 35¢$2.80/day
Same stage, same baby — the only variable is the pack you reached for.
Skip (this stage punishes it)
A full pouch-only food default at three meals a day.
Shoes for a crawler. Socks with grips do the job for a fraction.
Doubling every purchase 'for daycare' before asking daycare what they supply.
Your two numbers for this stage
Diaper changes a day: 8 — at a 24¢ model diaper that is $1.92/day, or about $58/month. Keep your real unit price under your written target and this stage is handled. Everything else this quarter is commentary.