How much do they cost in total?
'Totale' — 'to-TA-le'. Three syllables, stress on second.
When buying multiple items — shoes plus care products, for example. Checking the total before going to the till.
'In totale' = in total. 'Costano' is third-person plural of 'costare' — used because 'scarpe' is plural. 'Quanto costa?' for a single item; 'Quanto costano?' for multiple.
Quanto vengono in tutto?
How much does it come to altogether?
'Venire' used for cost — very Italian: 'viene/vengono'
Il prezzo è tutto compreso?
Is the price all inclusive?
Checking for hidden extras
C'è lo sconto se prendo tutto?
Is there a discount if I take everything?
Asking for a bundle discount
Asking for a small round-number discount on a total purchase is perfectly acceptable in Italian independent shops. The key is to do it politely and at the end, not at the start. It's a sign of an engaged customer, not a cheapskate.