Product X is priced at $200 and customer will get it in 5 days.
Product X is priced at $100 and customer will get it in 20 days.
What are customers thinking? Would most rather get it in 20 days at a lower cost?
It's a misconception that most people focus solely on price when making a buying decision. There are a lot of other factors that can be in play.
When it comes to time, many people want to have stuff asap, and having to wait 20 days is a long time. So, I think the majority of folks would choose to go ahead and pay the $200 for the convenience of getting their product in 5 days.
You can test this out, of course, but just go ask your friends and family members.
If you could have a brand new game system (or whatever product) in 5 days for $200, would you buy it?