Cost of having engine bored?

I give up on understanding how to read my slide micrometer. If my 1980 honda xr 80 is bored .25 over from stock i'll just buy a .50 over piston and ring kit. I'll bring new piston and cylinder to a bike shop and have them bore it so my piston fits. How much does having a cylinder bored out cost. Also is there someone on here i could mail my cylinder to and let them pick a piston and bore bike out for me. Where i live there are only two bike shops. One is too high and other is way to high to deal with