Swiftsure's refit was cancelled halfway through, at which point her original armament had been removed but not yet replaced (planned fit was identical to the Tiger class, two twin 6"/50 mk26 turrets in 'A' and 'Y' positions and three twin 3"/70 mk6 in 'B', 'P' and 'Q' positions). Her new bridge and lattice masts were in place, but the bridge did not have any windows cut before the cancellation. In terms of shape it was closer to that fitted to Belfast during her mid fifties modernisation, three sided at the front instead of flat like Tiger's. Two stories circulate as to the reason her refit was cancelled, first that during the refit she was found to have suffered serious structural damage to her hull during a collision with HMS Diamond in 1953. Secondly, it was cancelled because gun armed cruisers were virtually overnight now regarded as obsolete (the last two Tigers, Lion and Blake were still to complete at this point, so if this was the case why were they not cancelled immediately?) and the refit was costing far too much to produce an obsolete (ie non missile armed) ship. Another cruiser, HMS Superb, had also paid off pending a similar refit but this was not begun and she went for scrap shortly afterwards.
Although the refit was expensive, even after adjusting for inflation it didn't cost "many billions"!
But overall, it does contribute to a picture of the RN's intended cruiser force planned for the early 60s in the mid 50s. The existing Town class and Crown Colony class cruisers were wearing out despite refits, large scale new construction was out of the question for at least another decade so to bridge the gap (to the 70s) the RN would have had effectively five Tiger class (Tiger, Lion, Blake, Swiftsure and Superb) supplemented by the modernised Belfast and Sheffield, though the latter two would not have been expected to serve beyond the mid to late 60s.