I did not ever see 2-7 spread anywhere in Vegas.
As for cheap blackjack, Slots-A-Fun will be a good bet for you since it is very close to the Stratosphere. Circus Circus also has a good deal where you can buy nonnegotiable chips, something like $10 for $15. Ask at the funbook desk.
For a good guide to cheap vegas stuff, including cheap gambling, see the
Cheapo Vegas web site.
I am told that the Orleans has good cheap tourneys.
That's all. Have fun!