FGMM is cheap. About 1.20 a round plus or minus. It should meet your criteria.

http://palmettostatearmory.com/feder...bthp-20rd.html

https://www.ammunitiondepot.com/807-...rain-bthp.html

http://www.targetsportsusa.com/feder...8m-p-1163.aspx

You could try the 175's also but if you have a light rifle the recoil may be a little higher. I find that these will give smaller groups in most 1:10 rifles.