The cheapest option if you like stone is to get a very commonly available (and less expensive) granite like uba tuba. Go to the nearest stone supplier which has a warehouse and ask them to show you their least expensive granites.

And consider going to multiple stone yards/ fabricators. Costs vary a lot.

Menard's carries a few quartz which are actually made by a reputable company (HanStone) under a different name. The lowest sell for $35 sq. ft. on sale. I have received mixed information as to whether this price includes installation. I have just began to look into it.