What Yarn to Get? Beginner!

[oliviap5]

Hello! I posted a question a little while ago asking whether or not this would be a good sweat pattern for a beginner. http://www.berroco.com/patterns/peter-easy

I got the 'ok' and am excited to start it soon! The only problem is that I am really unsure as to what yarn to buy. The yarn they recommended for this pattern is apparently 'discontinued'. So I am looking for another type of merino yarn that isn't going to cost me a fortune.

Do any of you have good recommendations as to where to find good yarns?

And there also seem to be a lot of 'merino' yarns, and I am not sure which one to get for this pattern?

Thanks!