Businesses need to make a profit to stay in business. Most people, and clearly the original poster is in this category, don't have any idea how much it takes to keep a business profitable. If you think you can do it better and cheaper, I would encourage you to do so, but I think you'd be in for a rude awakening.
Out of that markup comes inventory costs, insurance costs (building, vehicle, health, life, liability, workmans comp, etc), taxes (payroll, county, state, federal, social security, property, vehicle), wages (for the service person, warehouse personnel, office personnel and owner), property costs and maintenance, vehicle costs, ongoing training for service personnel, office overhead, and a host of other items. Amazon can sell the items cheaper because of their sheer volume, size and ability to negotiate deep discounts with suppliers. Even a moderate size business simply can't compete at that level, nor should they be expected to.
Do you also whine and complain when you go to a restaurant and have a dinner for two that costs $38 plus the tip, when the same dinner would cost you $11 if prepared at home? Have some wine with that dinner and the markup on the wine is around 400%. Have a soda with that meal instead of wine? The markup is about 1,100% on the soda.
Do you have a text plan with your phone? The markup is around 5,000% on texts. Valentine's day roses for your sweetie? It's around 220%. Taking her to a movie? About 192% just for the tickets. Having popcorn with the movie? It's marked up about 900%. Yet I didn't see you post anything about those massive markups.