You can, but why have the downtime and deal with breakdowns all the time??But don't you think the cheap mower has virtual also? For one, they are lighter.....a lot lighter so it is so much easier to throw it into the bed and take it down. This become important if you are in more dense area where you do a lot of small jobs.
Also you can get 5 cheap mower for the price of one commercial one. You just use until it breaks and throw it away. No need to deal with dealer of expensive maintenance.