(to) gather d............
(to) gather dust
to be) all the r.........
to be) all the rage
(to be) old h......
(to be) old hat
cost an a.... and a l.......
cost an arm and a leg
(to be) out-of-d...........
(to be) out-of-date
c...............'s play
child's play
the c......... of the c........
the cream of the crop
(to be) m................-of-the-road
(to be) middle-of-the-road
to be u...........-friendly
user-friendly
get the h........... of something
get the hang of something
be in good s..........
be in good shape
be on your/its last l.........
be on your/its last legs
not break the b...........
not break the bank
(to) come in h.........
(to) come in handy
on the b..........
on the blink/fritz