Start up costs ~ using a standard Langstroth hive and typical protective clothing and tools ~ is roughly $350. plus bees which are about $100.
http://www.mannlakeltd.com/beekeeping-supplies/category/page3.html
The price can go up or down depending in what you choose.
After the initial start up costs ~ the are not a lot of monthly expenses. We feed ours in the fall, so we do buy white cane sugar by the 25 pound bag. We have 20 hives so we do buy quite a few of them.
If you choose to treat for varroa mites ~ there is a small cost there.
Some people never buy any "extras" and others spend a lot. My husband like to have all of the "toys" so we have spent a little more than we would have had to. This is our "Retirement Hobby" and we don't travel or spend money on fancy cars, clothing or jewelry ~ so we splurge a little here.
Extracting equipment can be expensive if you choose to buy it. Many Beekeepers' Club have extractors that they will loan out.
Mann Lake is a good source for equipment as they have free shipping over $100. Wood is heavy and shipping can be expensive. I also suggest looking for a local supplier of wood ware if you can find one.
We check our hives about every 10 to 2 weeks during the spring and summer. We can do all 20 hives in a day. It should take less than an hour for a beginner to check one hive. They take much less time and effort to care for than chickens.
I suggest you try to find a Beekeepers' Club in your area and start attending meetings. The best time to start a hive is early spring. Late summer and Fall are not good if you live in an area with cold winters. I'm not sure about areas in the south and west where it maybe much milder.