I have two Kenmore compact window air conditioner units that I no longer use. I used them not this past summer but the summer before and they worked fantastically. They've been in basement storage since then. They are clean, including the filters, and they're ready to keep someone else cool.
One is 5,000 Btu (model# 580.75050801 and the other is 5,150 Btu (model# 580.75050500). Aside from that, they are the same. Both with new side curtains to make placement in your window a snap.
Take one for $75 or both for $125.