I put on 75 yds with a backer, then after the season I reverse it so I get another year out of the new stuff underneath. I used a Range finder to measure of 75 yds. I have been doing that for XX years and have never had a problem. I probably fish more than the average guy too.
A 300 yd spool at Cabelas is $41. It will fill 4 reels and you will get 2 years out of it. That's only $5.00 per reel per year.
Have a good day