I pretty much buy quality fly lines that are on sale. Fly lines are an expensive, consumable item that can be ruined fairly easily. Some fly lines last a long time and some don't. I would rather spend $45 on a fly line that lasts a year or two than spend $80 on a fly line that lasts a year or two.

Most RIO, SA, and Airflo lines that I have used have worked well for me. It is pretty easy to find a type of line that I want to use on sale.