August-September is a good time to start sending inventory into FBA for these and building SEO on the listing. Sales might be slower during the summer, but we are approaching the holidays and winter in the US. The deadline for holiday inventory is mid October, so August would work well.

Pricing none of us can answer - make a spreadsheet of all of your costs including tariffs and logistics, add in Amazon fees, then create a selling price with a wide enough profit margin to ensure you are receiving a profit. You can research similar products to make sure you are priced competitively, but you also want to make sure you are not losing money.