Sometimes, a good price can be a bad choice, but it is usually alright to purchase toys found at garage sales. Just be sure they are safe for your child to use and are in good condition with no broken parts or sharp edges. However, never buy a car seat from a garage sale, even if it appears to be in good condition. You can't be sure that it was not involved in a car accident. Regarding the swing you purchased, check with the manufacturer to ensure that it is still safe to use. Be sure to request instructions if you didn't get them.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.