Pricing engraving query

[Stewey]

HI , I did a search, and read what I could, but haven't readily found an answer to this:

I'm after an approximate price (or value of the job) to engrave and cut out 20 plaques, in 2mm aluminium, 90 x 50mm size. Lettering engraved about 0.5mm deep, plain single-stroke letters, eg 'Panel donated by Joe & Marg Green, Highland Plains' and then the letters blacked.

I'm new to cnc cutting, and don't want to underprice the job. I know overheads & material costs etc all come into it, but I'd be keen to know an average value for a job like this.

Thanks!