There are a number of reasons you should not be buying major equipment for your pressure washing business from a Big Box store; Home Depot, Lowes, or Wal-mart.
1. Most of this equipment is foreign, European or China made. These will have Metric measurements for their fittings so they will not attach to US (imperial) measurement hoses and other equipment unless you get and use adaptors. The more attachments you have the more chance for pressure loss with leaking.
2. The initial price will be cheaper because it is foreign made using cheaper labor, but you will have trouble finding and getting replacement parts. The Big Box stores only sell new units not parts.
3. Inferior materials. With some equipment parts like pumps found on residential pressure washers, they can be made from cast aluminum, not harder metals so they can easily warp from the heat of heavy use.
4.Hard to find and get parts. Since parts must be source overseas many things like pumps do not have repair kits available, you would have to buy an entire new pump to fix an issue. Or if you can order parts there will be a long time factor to get them here to the US, especially these days.
5. Harder to find shops to work on this equipment. Again because they are foreign made, even when you can find parts, repairs can be difficult with no readily available support documentation, no breakdown drawings, etc.
The alure of a cheap price may be appealing at first, but the first time you have an employee drop a surface cleaner off a curb and bend a bar, how great is that $250 price over the similar US $450-$600 unit? You now have either wasted that money and are loosing business or until if and when you can get it repaired. There is a big reason the Big Box stores sell these cheaper units, they consider them consumer disposable units. This equipment is not for the commercial business contractor. There is wisdom in the old adage "Buy the best you can once, instead of cheap over and over."