Consider buying big-ticket items in the order “borrow, buy used, buy new” — don’t buy them all at once

Short-lived purchases such as strollers, blankets and toys can be borrowed first, bought used second and bought new last. A used car seat needs a known crash/recall history and complete parts; do not use it if these cannot be checked. A Scottish case-control study associated previously used infant mattresses with about threefold SIDS odds, without establishing causation; the author prefers a new mattress.

No extra money is needed; the amount saved is usually in the thousands of yuan. The hard part is resisting the urge to buy everything at once.

The money-saving principle is the author's experience. Three safety boundaries accompany it. US NHTSA says to replace car seats after moderate or severe crashes. A crash counts as minor only when the vehicle can be driven away, the nearest door is undamaged, nobody is injured, airbags did not deploy and the seat has no visible damage. Its used-seat checklist requires no moderate/severe crash, a manufacturing-date/model label, no recall, complete parts and the instructions; the label permits recall and age checks. A Scottish case-control study associated routine use of another child's mattress with SIDS: OR 3.07 (95% CI 1.51–6.22). Estimates were 4.78 for mattresses from another home and 1.64 for those from the same home, the latter not clearly different. The authors said evidence could not establish that the mattress caused the association. US crib standards effective June 28, 2011 also apply to used cribs and eliminated traditional drop-side designs. CPSC says destructive testing is required to establish compliance, preventing a home self-check. From November 2007 to April 2010, 147 deaths involving full-size cribs were reported in the US; 35 involved structural problems, 18 drop-side failures and at least 10 loose screws. US law banned inclined infant sleepers regardless of manufacture date, with implementing regulations in 2023.

The original grade remains C because the saving-money principle lacks direct research. The safety sources are from the US and UK; the original author found no dedicated Chinese official guidance for used cribs or seats. A 1997 BMJ letter questioned whether income and bed-sharing confound mattress associations. See section 1, item 10 for child car seats, and this section's item 1 for safe infant sleep. This guide neither endorses nor rejects postpartum centers, early-education classes or baby swimming; they are optional large expenses to which section 5's 24-hour cooling-off rule applies.

省钱部分为作者经验，无直接文献；US NHTSA. Car Seat Use After a Crash. https://www.nhtsa.gov/car-seats-and-booster-seats/car-seat-use-after-crash；US NHTSA. Used Car Seat Safety Checklist. https://www.nhtsa.gov/car-seats-and-booster-seats/used-car-seat-safety-checklist；Tappin D, Brooke H, Ecob R, Gibson A (2002). Used infant mattresses and sudden infant death syndrome in Scotland: case-control study. BMJ, 325(7371), 1007. https://doi.org/10.1136/bmj.325.7371.1007；Blair P, Fleming P, Smith I (1997). Case-control study of sudden infant death syndrome in Scotland. Income level or bed sharing would confound any effect of previous use of mattress. BMJ, 315(7111), 812. https://doi.org/10.1136/bmj.315.7111.812a；US Consumer Product Safety Commission (2010). Safety Standards for Full-Size Baby Cribs and Non-Full-Size Baby Cribs; Final Rule. Federal Register 2010-32178. https://www.federalregister.gov/documents/2010/12/28/2010-32178/safety-standards-for-full-size-baby-cribs-and-non-full-size-baby-cribs-final-rule；US Consumer Product Safety Commission (2023). Ban of Inclined Sleepers for Infants. Federal Register 2023-17350. https://www.federalregister.gov/documents/2023/08/16/2023-17350/ban-of-inclined-sleepers-for-infants；冲动消费见第 5 节