[RBS] Cost of a mini-mercazi installation for a 5 room apartment?

[Goldstein]

I'm negotiating rent with a landlord, and we need to know the approximate
cost of installing a mini-mercazi a/c in a 5-room apartment.  I'm just
asking for an estimate, from those of you who've done this somewhat
recently.  Are we talking 12,000 NIS, 15,000 NIS, 20,000 NIS?  

Please give me a general, realistic ballpark figure for such a thing these
days.

Thanks.

Avram Goldstein