Are Allison and Oblak the only 2 keepers on the planet? For what it's worth I actually agree with the club in the sense that no way is that Allison worth £60m and Oblak is not worth £100m either. That shouldn't mean we stop looking though.
What I would say is that our defence did improve dramatically over the second half of last season, after conceding 5 against City, 4 against Spurs, 3 in 5 minutes against Arsenal, 3 against Watford and even 3 against Seville in that embaressing second half capitulation over in Spain we seemed well on course to ship our usual 50 goals for the campaign but the brakes came on quite dramatically once VVD and Karius were introduced to the side.
In fact we ended the season conceding just 38 league goals which was our lowest total in a decade (since Rafa's day) which just shows you how dramatically the brakes were slammed on.
CL final aside our defence was improving and with the introduction of 2 top class DM's in Fabinho and Keita (in an interview with LFCTV he described himself as primarily a defensive player) you'd imagine our defence will improve even further.
If Karius looks jittery we can always throw Ward in who looked a good keeper at Huddersfield to be fair.