If you just want a "I'm sending lead down range for fun" plinking round then buy a cheap bulk bullet. The 55gr Hornady FMJ may work.
I have had good luck with Varget, AA 2015, Benchmark, and VV N133.
H335, RL10x, N133 are best for bullets below 50gr N133 produced great accuracy in my rifle with velocities in the 3700 fps range.
AA 2015, Benchmark, H335, H4895, TAC are best used on bullets 50 to 60gr
My goto ground hog load is a 50gr vmax and a stiff load of AA2015. It give good accuracy and good velocity.
AA 2520, N540, Varget are best for 60 to 70gr bullets. Varget can be used for lighter bulets. But While I had decent accuracy (.6 to .7" 5 shot) it is better for the heavier bullets.
Varget, Reloader 15, N140, N550 reloader 15 is a great powder and is used a lot in the 308 with 175gr SMK for F-class shooting. VV N550 is another great powder it is hotter than N150 which is exactly the same except for a single coating additive they add.
For a low cost round I would fine the cheapest bullet and then go with the powder that offers the lights load weight for a given velocity. Primers you can use what ever you find cheapest.