little
There was no money left over for luxuries or little extras.

optional (BrE)
hidden (esp. BrE)
£400 is a lot to pay, but there are no hidden extras.

added
Regular guests also get added extras like free room service.

DVD
The DVD extras include trailers and a behind-the-scenes feature.

have, include
The DVD has a couple of interesting extras.
No extras are included.

include sth
Optional extras include anti-lock brakes and an electric sunroof.

Extra is used with these nouns:
attention, bonus, boost, bulk, burden, calorie, care, cash, caution, charge, confidence, convenience, copy, cost, credit, demand, dimension, distance, edge, effort, emphasis, encouragement, expenditure, expense, facility, fat, feature, fee, finance, flavour, flexibility, fund, funding, help, helping, impetus, incentive, income, information, ingredient, investment, layer, leverage, material, money, motivation, precaution, premium, profit, protection, push, ration, refinement, resource, revenue, risk, room, safeguard, safety, sparkle, spice, step, storage, strength, supplement, support, thanks, troops, tuition, twist, vigilance, weight, work, workload