Comment Various options (Score 1) 172
Take a look at the sigrok project. We have rather a lot of experience with low cost lab gear.
For a long time the best option for a standalone scope has been the Das Oszi scopes, sold under the brand names Hantek, Protek and Voltcraft. As a bonus, a guy name tinhead has reverse engineered the schematics. Hopefully we'll have it supported in sigrok very soon.
There's also the SmartScope for ~$180.