Might look at the LaCrosse WS-7013BZ-IT. MSRP is $26.95 and will accept inputs from 3 sensors.

Have you thought of Weatherbug? Depending on where you live they can have data from a number of local stations.

My Radio Shack handles three channels and has a high/low memory but I think that to get more than one remote sensor will cost more than $30.

Were I shopping again I think I would consider looking on Amazon. Who knows what they may have.

I've had a LA Crosse WS-9625U-IT for several years. It will accept 3 sensors.
The manual recommends alkaline batteries, but I believe I've read that for extreme low temperatures, lithium batteries be used in the sensors.
It's been so long since I've changed the batteries in mine, I can't remember what kind I have.