There are many places where you can buy men's rubber boots. Except for online stores like Amazon, Walmart or Target, there are some popular rubber boot brands like KalKal Boots, Bogs, Muck Boots Company, Huk, you can check their sites to find the ones that fit you, and also you will see more related sites on the search results for reference.
One can find men's rubber boots on the L. L. Bean website, Cabela's website, and on Amazon. Men's rubber boots can also be found in stores such as Walmart or Lowes.
Mens dress boots are available at any good department store as well as online at sites such as Ebay and Amazon. In the UK, stores would include Debenhams, John Lewis and British Home Stores.
One can buy mens walking shoes online or locally. Online sites include Sports Direct, Outdoor Gear Lab, Macy's or Sierra Trading Post. Locally one can check the telephone directory for shoe and sports stores.
Rain Boots can be purchased anywhere. In a store, or it can be bought online. One can buy Rain Boots on eBay, Amazon, Target or any other site that provides these kind of products.
ebay.com
Zycon.com has rubber baskets you can buy online. You can go to google and look for more places to buy online as well.
Online, west of old England, some feed stores, country stores, boot or shoe store. Your best bet is online, maybe ariat.com. Buy leather for English boots. Trust me, yes they are more upkeep and more expensive but they last longer and your feet with thank you in the long wrong. I personally never get synthetic boots of any kind, not western boots either. Only boots I have that are "synthetic" are my rubber boots
You can buy kids' rain boots online at zappos.com. One such rainboot I found is http://www.zappos.com/hatley-kids-rain-boots-infant-toddler-apple.
in online stores
You can find buy snowboots online at: www.snowbootsonline.com/
One can buy black flat boots through many online retailers such as Overstock, Macy's, and Nordstrom. Online auction sites such as Ebay would also be a good option to buy black flat boots.
I doubt you have enough money to buy mens running warehouse but if you want to buy running apparel then you can check your local sports stores and online at retailers.
Snake Boots can be purchased from a number of retailers online. One can buy such boots from Amazon for prices between $60 and $260. They can also be bought from eBay and Rocky Boots.