It seems like 5 seasons is the breaking point for SyFy. by the time a show gets to 5 Seasons, it's true their set budget should be less, because by the time of reaching 5 Seasons you've likely got most of the sets you need for day to day episodes. However, it's also the point at which the salaries start to become to expensive for ratings a SyFy show gets, so, it probably comes down to a choice between an all new cast (Or at least replacing the most expensive lead(s)) or cutting the cast down to practically nothing
And really, a SciFi or Fantasy show making it to 5 Seasons is pretty much a rarity on US Television anyways. And really not a large percentage of shows in any Genre make it to 5 Seasons
We had the Trek shows (TNG, DS9, VOY), the Posthumus Roddenberry Shows (Andromeda and EFC - Both of which sank rather low in S5 with Budget cutbacks...Andromeda being stuck in one place; EFC cutting the long running cast). The Stargate shows (SG1 and SGA), Babylon 5 and a few other SyFy shows. (Sanctuary, Eureka maybe others?) and I guess you could also include LOST and Fringe. Can't really think of any more off hand
And really, a SciFi or Fantasy show making it to 5 Seasons is pretty much a rarity on US Television anyways. And really not a large percentage of shows in any Genre make it to 5 Seasons
We had the Trek shows (TNG, DS9, VOY), the Posthumus Roddenberry Shows (Andromeda and EFC - Both of which sank rather low in S5 with Budget cutbacks...Andromeda being stuck in one place; EFC cutting the long running cast). The Stargate shows (SG1 and SGA), Babylon 5 and a few other SyFy shows. (Sanctuary, Eureka maybe others?) and I guess you could also include LOST and Fringe. Can't really think of any more off hand