Wall mounted desk plus shelfs

We would like to get a quotation for a 250x100 wall mounted desk and two shelfs 250x30. The material should be cheap. The desk and support should be strong enough to hold about 20kg ( two monitors, a printer and few more things) so nothing special. We have only one wall in the back of 255cm and one on the right side deep 100cm. On the left there is a door so there can’t be a wall.