How much yarn do I need?

Hello, dear forum!
I bought an English pattern for a 2C2 baby blanket.

Unfortunately, I don’t understand how much yarn I need or how big the blanket will be.
Here’s the information I have:
- The number of stitches per color
- The number of meters per color
- The crochet hook size (3.5)
- Medium Yarn

So there’s a table that lists the color first, followed by the number of stitches and meters.

I’ve added up the total number of meters. That would be 3,695 meters (!)
The yarn I’d like to use has a length of 50 g = 75 m.
Gauge: 10x10 cm = 20 sts x 24 rows.
So that would mean I’d have to buy 50 skeins of yarn?
Isn’t that a bit much?
Did I misunderstand something?

I hope you can help me out!
Best regards, Jen

Hi Jen, 
What I find inconsistent is that with a yarn yardage of 50 g = 75 m, the gauge is 20 stitches (double crochet?) for 10 cm. That can’t really be right... or did you seriously use a 3.5 mm crochet hook?

Best regards, 
Michaela