yes it is very possible to get a decent british sxs for a few thousand dollars. Its hard with british guns to buy using a makers name. Each gun must be viewed as an individual, as most Brit makers offered a wide variety of quality levels, with most all of them being servicible at the time of purchase. Many of these guns have been refreshed several times, and can (as Lowell pointed out)
end up with thin barrel walls. Barrel condition is very important when re-selling British guns. Also look at gun fit. There was a much wider variation among older British sxs stock dimensions than among our american counterparts. Consider sending a perspective purchase to a gunsmith who is familiar with sxs's to have him inspect your gun before purchase. Feel free to email me off-line with any other questions. I enjoy helping folks get into British guns.
Steve