IMO, the German K98k, all manufacturer codes, prior to late 1944, will be better made, fitted, and generally function better than an M48.
The M48's tend to have a stiffer bolt function on cocking(opening), and very stiff safeties.
Triggers are a wash between the two.
Accuracy wise, I have seen little difference.
M48's still seem to be available locally, and cost less.
K98k's so dated were of WWII origin, and in whole or part, were issued at that time (taking parts guns into consideration).
Some M48's may have been used in the Balkan conflicts, but they are not as sought after by collectors, which affects there price, along with the relative quality issues, and the intermediate safety breeched action, which affects alteration and aftermarket support (not quite as much stuff made that fits that action).