Collocations for expensive - adj.

be, look, prove, seem, sound
Her suit looked extremely expensive.

become, get
Food in this country is getting very expensive.

make sth
Adding these safety features would make the cars too expensive.

find sth
I found the food very expensive.

extremely, fairly, very, etc.
amazingly, astronomically, enormously, exceedingly, extortionately, extremely, hideously, highly, horrendously, horribly, hugely, incredibly, insanely, ludicrously (esp. BrE), massively, outrageously, prohibitively, ridiculously, ruinously (esp. BrE), terribly
Some of these legal cases are enormously expensive.
Giving every patient an annual flu shot would be prohibitively expensive.

moderately
a little, slightly, etc.
increasingly
comparatively, relatively
notoriously
obviously

Expensive is used with these nouns:
boutique, champagne, cigar, clothes, coffee, commodity, cosmetic, cut, delicacy, end, equipment, exercise, fare, flop, gadget, gift, habit, hobby, hotel, house, import, item, jewellery, lifestyle, litigation, luxury, mistake, option, perfume, proposition, purchase, repair, restaurant, shop, suit, taste, toy, undertaking, venture, version, waste, wine