Big fan of wool here. I have lots of merino wool, lambs wool, etc.
I prefer 100% hands down, but.. I do have some 80-20 and 60-40 blends that are usually some kind of wool/poly and they are still effective.
But.. Good wool is worth the investment and care.
I watch sales at men's stores. The suit places. I do not wear suits, but those types of places usually have V neck lightweight wool sweaters at either deep discounts or on some kind of "buy one get three" deal. Obviously they are intended for less casual wear, like with a tie and undershirt, but.. they work terrifically well for hiking and bicycling by themselves.
Here in my area there is Jos. A. Bank:
http://t.josbank.com/menswear/shop/Product_11001_10050_330449Right now their basic merino is listed at $109 USD, but I bought four for $90 USD in December during their Christmas sale that happens every year.