A listing with Variations is charged a single insertion fee

1. Do i save money on insertion fee when i list only 1 item but with 4 variations (S,M,L, XL). Or eBay charging insertion fee for each variation?

2. From search point of view. Is it better to have 1 listing with dropdown to choose size or better to have 4 listings and hope buyer will find his size "somehow".

#2 is arguable. When you have 1 listing you have 1 chance to come up in search. If person landed on it, liked the dress, ends up picking his size and you have an order. When you have 4 listings you have 4 chances to come up in search, but then person lands on M size listing, but needs L size so person ends up on clicking one of the eBay's suggested items from my competitor. So no sale.