Choosing a DSO, advice sought
Don't expect to see much in that 315/433 MHz band if you try to scope it with a 50 MHz scope.

1 GS/sec is also subjective. Some scopes will do this per channel - others will share the 1 Gs over all channels.

Also, depending on the probes and connection methodology, it can be difficult / impossible to see high-speed signals accurately regardless of the scope.

For digital debugging, you may find more value-per-dollar if you look into logic analyzers - you get more channels and higher bandwidth at the expense of the flexibility that a scope can give you in the analog domain.