$re = qr[^\s*(?:\d+-\d+)(?:\s*,\s*\d+-\d+)*\s*$];;

print "$_ : ", $_ =~ $re ? 'ok' : 'bad' 
    for '1-5, 20-250, 37000-41000', '1-25', '1-25,67-324', 
    '1-15, 76-102, 56-98', '1-25,28-43.5', '1-2a, 45-98';;

1-5, 20-250, 37000-41000 :  ok
1-25 :  ok
1-25,67-324 :  ok
1-15, 76-102, 56-98 :  ok
1-25,28-43.5 :  bad
1-2a, 45-98 :  bad